Archive for the ‘HPV’ Category

From plant virology to vaccinology: a personal journey

15 February, 2017

A couple of years ago now, an Editor of the journal Human Vaccines & Immunotherapeutics contacted me to say they would like to profile me as a vaccinologist. Being of a suspicious nature, I immediately inquired how much this would cost me. The encouraging answer was “Nothing!” – so I jumped straight in.

The end result is as near to a current autobiography as I will probably ever get, so I may as well put it up here. So, if you’re interested in finding out what the connections are between a swimming pool in Zambia, not doing Biochemistry (twice), plant virology and making vaccines – click below!

The Internet Journal of Comprehensive Virology

15 July, 2016


See Home Page for details

New Approaches to Vaccines for Human and Veterinary Tropical Diseases. Or maybe sophisticated safari science?

27 May, 2016

The Keystone Symposia organisation held a meeting entitled “New Approaches to Vaccines for Human and Veterinary Tropical Diseases” in Cape Town this week (May 22-26, 2016).  A summary of the meeting was given as:

Human and livestock vaccines can contribute to improved human welfare and income generation by maintaining human health and meeting the demand for meat, milk and fish in developing countries. All of these factors contribute to the growing importance of improving food safety, availability and nutritional security. An important component of this Keystone Symposia meeting will be to stimulate crosstalk between the human and veterinary vaccine communities by highlighting cross-cutting technical advances and new science and knowledge from laboratory and field research. The meeting will also provide a rare opportunity for scientists from the Northern and Southern hemispheres to interact and pool resources and knowledge in the common fight against tropical diseases.”

It succeeded admirably in a couple of these goals: there were delegates there from 31 African countries, as well as many Europeans, Brits and Americans; the juxtaposition of veterinary and medical talks on similar themes created an excited buzz among folk who hadn’t been exposed to the “other”; there was a wealth of dazzling new tech on display in talks, and intriguing insights into how similar – and sometimes, how different – human and animal responses to vaccines were.  It was obvious that approaches used to develop malaria vaccines could benefit animal vaccinology, and indeed, Vish Nene and colleagues from ILRI in Kenya are following some of the same approaches in their work with the East Coast fever disease organism in cattle.

But, there were a couple of buts.  An important one for me was that while there were many Africans there, they were not much exposed in talks, apart from several South Africans. While amazing results were displayed from deep sequencing of antibody gene repertoires of humans and animals and how these developed with affinity maturation; while grand predictions were made as to how bioinformatics and molecular design would revolutionise vaccinology – this was more of the same kind of thing we have got used to in HIV vaccine meetings over nearly twenty years, where Big Science is always going to provide a solution, but never quite gets to it. Why was there no mention of ZMapp antibody therapy for Ebola, when this (OK, I’m biased) was the single most exciting thing to come out of the Ebola outbreak and the international response to it?

I hate to be cynical, but seriously: is there one single vaccine in advanced human trial right now that is a result of intelligent molecular design? Has ANYTHING that has been designed from crystallographic evidence or from cryoEM data actually proven useful in animals or people?  Has dissection of the anti-HIV antibody response development actually, really, taught us anything useful about how we should develop vaccines? Even if South Africans were involved?

I told you I was cynical – and my cynicism was reinforced by a couple of displays of “My Ebola vaccine is better than YOUR Ebola vaccine!”, by folk who shall remain nameless – when it was obvious that both ChAdOx and rVSV vaccines have their merits.

Mind you, the tale of how Ebola vaccines were deployed so rapidly, and how what could have been a 15+ year saga was compressed to less than a year for the rVSV-ZEBOV and ChAdOx vaccines was truly inspirational. It is indeed an object lesson in how to respond to an emerging disease that big companies and philanthropic organisations were able to make many thousand doses of different vaccine candidates in just a few months, and that these could be deployed in human “trials” – actually, genuine deployment in ring vaccination for the VSV candidate – almost immediately.  Adrian Hill of Oxford asked the question, albeit outside the meeting at a seminar in our Institute: if this was possible for an Ebola outbreak, why isn’t it possible for everything else?  Why can’t we do it for Zika virus, and for MERS-CoV too?

If there is a Big Lesson to come out of this meeting, why can’t it be – Let’s Make Vaccines Faster!

Oh, there were big plusses too.  There were fascinating parallels to be drawn in the approaches to developing vaccines for malaria and TB and animal parasitic infections; some of the fancier techniques discussed for human vaccines could obviously find applications in veterinary vaccinology; there were even suggestions for vaccine candidates for animals that were drawn from homologous genes in human and animal apicomplexans (=malaria-like organisms).

I was especially impressed by Dean Everett‘s talk, from the Malawi-Liverpool-Wellcome Trust Clinical Research Programme in Malawi, on “Developing Appropriate Vaccines through Bioinformatics in Africa”: they were actually working in under-developed Africa, on pressing local problems, and making significant inroads into the problems.

And yet, and yet: I have railed elsewhere about the J Craig Venter Institute’s grandstanding over their “synthetic” organisms; while the talk here by Sanjay Vashee on “Synthetic Bacterial and Viral Backbones as Antigen Delivery Vehicle” went some way to redeeming my negative impression of the use of this sort of work, I am still left with the impression that there are considerably easier ways of doing what they claim to be able to. Mind you, one of my colleagues was very impressed with the possibility of making Herpesmids (=infectious, engineerable whole genome clones) in yeast, and would love to do it with their poxvirus collection – so maybe I am a touch TOO too cynical.

I also felt that the final address, by Chris Wilson of the Bill & Melinda Gates Foundation, on: “Cross-Disciplinary Science to Accelerate the Discovery of Vaccines for Global, Zoonotic and Emerging Infectious Diseases” exemplified some of the problems inherent in trying to marry up developed and developing world science, especially in vaccinology.  Part of the talk was great: he gave the best description I’ve yet heard of why it could be feasible to inoculate Aedes spp. with Wolbachia, and why it could significantly impact transmission of flavi- and other viruses.  His description of gene drive technology for wiping out selected mosquito populations was also succinct, and masterly – and appropriate for a developing world audience. Then he got on to how dissection of antibody maturation pathways and flavivirus E protein design could provide paths to good vaccines, and the cynicism kicked in again.

We don’t need either technology to get to vaccines for HIV or for flaviviruses that we can test in the near future, and which could have very significant impacts on millions of people.

Really: we don’t. Extant HIV vaccine candidates are almost certainly better than the RV144 Thai trial vaccine components, and they had an efficacy of 60% in the first year. We already have YFV and dengue and JEV live vaccines – why don’t we use one or several of them in combination with an engineered YFV vaccine to protect against ALL epidemic flaviviruses?  Given the Ebola example, we could deploy vaccines for HIV and for flaviviruses in a year or less, and they would have an impact that would tide us over while fancier products were being made. Seriously: we are always waiting for the next best thing; let’s just apply what we know and what we have NOW to make an impact – instead of, like theoretical physicists, perpetually considering the problem of the spherical horse instead of just going out and riding one.

And that should have been one of the Big Lessons, and we missed it. Instead, there was an element of Safari Science, which is what we in Africa call the kind of endeavour which involves people from the global North flying in to sort out our problems – and leaving with our organisms and disease samples.

Which we could do ourselves, given funding. And that’s another lesson for the folk that do Big Science funding….


Your next DNA vaccine might come from tobacco

12 February, 2016

We don’t have much practice at this sort of thing, but seeing as we just got something REALLY cool published, and the man who largely made it possible is now a science writer, we decided to ask him to write a press release.  So he did.  Thanks, Paul Kennedy – take a bow, twice!

“In a pioneering step towards using plants to produce vaccines against cervical cancer and other viruses, University of Cape Town (UCT) researchers have generated synthetic human papillomavirus- derived viral particles called pseudovirions in tobacco plants.

“We’ve succeeded in making a completely mammalian viral particle in a plant – proteins, DNA, everything. That’s enormously exciting,” says Dr Inga Hitzeroth of the Biopharming Research Unit (BRU) at UCT.Dr_Inga_Hitzeroth

In an Open Access study just published in Nature Scientific Reports, BRU researchers report using tobacco plants to create a synthetic viral particle known as a pseudovirion.

A pseudovirion looks like a virus, but it contains no infectious viral DNA. A virus is usually made up of a shell surrounding the virus’s own genetic material. Pseudovirions instead carry whatever DNA the researcher wishes to include within the shell of proteins that make up the outer coating of the virus.

Until now, such particles have only ever been created in yeast or mammalian cell cultures – this is the first time researchers have successfully created pseudovirions in plants.

The BRU is part of a new movement known as biopharming, which means using plants as biological factories. Biopharming has been used to create flu vaccines, potential Ebola drugs, and an enzyme used to treat Gaucher’s Disease in humans. The technique employs the cellular machinery within tobacco plants or other plant cells to manufacture enzymes, antibodies or even the viral capsid proteins (the proteins that make up the shell of a virus), which act as vaccines.

In this research, the BRU has taken biopharming one step further by using plants to create a viral shell that encloses ‘custom’ DNA selected by researchers. “What’s unique here is that DNA that was manufactured within the tobacco plant is now being incorporated into a viral particle to form a pseudovirion,” says Hitzeroth.

The shell of this pseudovirion was that of human papillomavirus (HPV) type 16, the virus responsible for over 50% of cervical cancer cases worldwide.

The BRU team hope this new plant-based technology could one day be used to test future HPV vaccines. First author of the study, Dr Renate Lamprecht, renateexplains: “We need pseudovirions to test any new HPV vaccine candidates. At the moment it is very expensive to make pseudovirions – we need to make them in mammalian cell culture, it needs to be sterile, and the reagents are very expensive.”

All these factors contribute to the high cost of current HPV vaccines, which are actually virus-like particles. Virus-like particles (VLPs) are similar to pseudovirions, but they contain no DNA. Plant- made pseudovirions, as demonstrated by this study, could reduce the cost of testing and manufacturing such vaccines, thus helping to make HPV vaccines affordable where they are needed most: the developing world.


Plant-made HPV pseudovirions containing geminivirus-derived DNA

The BRU team compared these new plant-made pseudovirions against the more widely-used mammalian cell culture-produced particles by using what’s known as a neutralisation assay. In this test (which is commonly used to test new HPV vaccine candidates), cells are ‘infected’ with pseudovirions, with or without pre-treatment with neutralising antibodies. The DNA inside the pseudovirion carries a ‘reporter gene’ that produces a protein that can give off a light signal. Thus, an infectious pseudovirion gets into the cell and gives off light, but one that is stopped by neutralising antibodies does not.

“I was jumping up and down the first time I saw the neutralisation results, but I repeated the experiment a few times to be sure, asking myself, ‘is everything correct, are all the controls there?’” explains Lamprecht. “It was a very exciting moment for us when we confirmed that neutralisation had occurred.”

Right now, every laboratory makes pseudovirions for such neutralisation experiments themselves. Dr Hitzeroth hopes that one day, they won’t have to: “we’re in the initial stages, but if we optimise the process and get the yield much higher, we think it’s a product that could be sold all over the world.”

ed ebola

Ed’s Ebola shirt

For Professor Ed Rybicki, Director of the BRU, this achievement was enormously satisfying, as it brought together two strands of his research interests that have co-existed for over 20 years.

“Seventeen years ago, I had the idea to combine making HPV VLPs in plants with a DNA plant virus we were working on, to see if we could make pseudovirions. It took until now for the technology to finally come together, but it shows what can happen in biotechnology if you’re willing to persevere.”

The BRU are also hoping to use this technology to create a therapeutic vaccine, which would also be a first of its kind. The idea would be to use the pseudovirion to deliver DNA that could treat an ongoing HPV infection or even a tumour.

With global acceptance and support for the biopharming movement growing rapidly, it might not be too long before the first plant-produced HPV vaccine is making a difference in Africa and around the world.”

For further enquiries, contact Dr Hitzeroth. For more info on biopharming, check out this Q&A session from Sense About Science.

Testing out a textbook on Virology

5 December, 2015

Like my recent books on History of Viruses and Influenza, I’m constructing an ebook Introduction to Virology textbook – and I’d like people’s opinions.

It’s going to look something like this:



It will be based on my web pages that were so cruelly destroyed, but will be PROFUSELY illustrated, using all of the bells and whistles built into the iBooks Author app, with liberal use of Russell Kightley’s very excellent virus picture library.

And I will sell it for US$20 or less.

Tell me what you think of the taster – and there will be more.

Virology Africa 2015: Update and Registration

19 August, 2015


On behalf of the Institute of Infectious Disease and Molecular Medicine of the University of Cape Town and the Poliomyelitis Research Foundation, we are pleased to invite you to Virology Africa 2015 at the Cape Town Waterfront.


The conference will run from Tuesday 1st – Thursday 3rd December 2015. The conference venue is the Radisson Blu Hotel with a magnificent view of the ocean. The hotel school next door will host the cocktail party on the Monday night 30th November and in keeping with Virology Africa tradition, the dinner venue is the Two Oceans Aquarium.


Early Bird Registration closes – 30 September 2015
Abstract Submissions deadline – 30 September 2015

The ACADEMIC PROGRAMME will include plenary-type presentations from internationally recognised speakers. We wish to emphasise that this is intended as a general virology conference – which means we will welcome plant, human, animal and bacterial virology contributions. The venue will allow for parallel workshops of oral presentations. There will also be poster sessions. Senior students will be encouraged to present their research. We have sponsorship for students to attend the meeting and details will be announced later in the year.

A program outline has been added to the website


Our preliminary programme includes two workshops.

There is a hands-on workshop on “Plant cell packs for transient expression: Innovating the field of molecular biopharming”, with the contact person being Dr Inga Hitzeroth – This workshop will run at UCT one day before the conference, 30th November, and a second day, 4th December, after the conference.

The second workshop is on “”Viromics for virus discovery and viral community analysis”. The workshop at UCT will be on 4 and 5 December with the contact person being Dr Tracy Meiring –

Some of the workshop presenters will be integrated into the conference programme but the practical components will be run at University of Cape Town. Separate applications are necessary for each workshop.

If you are prepared to fund an internationally recognised scientist to speak at the conference or if you wish to organise a specialist workshop as part of the conference, please contact
Anna-Lise Williamson or Ed Rybicki.

For any enquiries please contact
Miss Bridget Petersen/ Email: or phone: +27 21 486 9111
Ms Deborah McTeer/Email: or +27 83 457 1975

Anyone interested? A candidate virology textbook…

28 July, 2015

I would like to test the response to a Introduction to Virology ebook that I want to develop from my extant Web-based material, given that this is likely to disappear soon with our Web renewal project here at UCT.


Download the Virus Picture Book excerpt here. And then please tell me what you think / whether you would buy one (projected price US$15 – 20)?  Ta!

The guru speaks: new eBooks on viruses!

24 June, 2015

I have to thank my long-time digital media guru, Alan J Cann, for reviewing our humble eBook offerings in MicrobiologyBytes.  You good man!  Much appreciated, and it will not have escaped our attention that this endorsement may actually result in sales.  If so, a glass or three of the finest red is yours if you come to these shores, good sir B-)

Papillomaviruses and human cancer

11 March, 2015

Human warts in all their forms – cutaneous, verrucous and genital growths and lesions – have been known since antiquity, and it was known since at least 1823 that at least some were infectious. Experiments done with human volunteers in the 1890s confirmed this, when it was shown that transplanting wart tissue resulted in typical disease.  As early as 1908, it was shown by a G Ciuffo that “verrucae volgare” – common warts – could be transmitted via a cell-free filtrate.  However, it was Richard E Shope who first showed that a papillomavirus was associated with animal tumours.  A useful review from 1931 on “Infectious oral papillomatosis of dogs” by DeMonbreun and the Ernest Goodpasture of egg culture fame covers the early history of the investigation of human disease as well as of animal papillomas very well, so we will not cover this further.

In light of later findings of the involvement of papillomaviruses, it was a prescient although premature observation by an Italian physician named Rigatoni-Stern in 1842 that cervical cancer appeared to be sexually transmitted, given that it occurred in married women, widows and prostitutes, but rarely in virgins and nuns.

Although papillomaviruses had been implicated as the first viruses known to cause a cancer in mammals as early as the 1930s, and the structurally very similar papovaviruses were similarly implicated in the late 1950s, it was only in 1972 that  Stefania Jabłońska proposed that a human papillomavirus (HPV; then called a papovavirus) was involved with the rare hereditary skin cancer called epidermodysplasia verruciformis.   

Meanwhile Harald zur Hausen had been investigating since 1974 the involvement of HPV in genital warts (condyloma accuminata) and squamous cell carcinomas, using DNA-based techniques such as hybridisation.  The rarely malignant condylomas had been shown to contain papillomavirus particles in some cases in 1968, with a better association in 1970; however, cross-hybridisation studies by zur Hausen’s group on DNA of these and common wart viruses showed no relationship despite their very similar morphologies. 

Virus particles from genital warts (6 &7) and a common skin wart (8).  Reproduced from Brit. J. vener. Dis., JD Oriel and JD Almeida, 46, 37-42, 1970 with permission from BMJ Publishing Group Ltd.

Virus particles from genital warts (6 &7) and a common skin wart (8). Reproduced from Brit. J. vener. Dis., JD Oriel and JD Almeida, 46, 37-42, 1970 with permission from BMJ Publishing Group Ltd.

Zur Hausen speculated on the role of HPVs in squamous cell carcinomas in 1977; Gérard Orth and Jabłońska and colleagues went on to define the “…Risk of Malignant Conversion Associated with the Type of Human Papillomavirus Involved in Epidermodysplasia Verruciformis” in 1979.

Because this was the new era of cloning and sequencing of DNA, the zur Hausen group and others went on to isolate and characterise a number of new HPVs associated with genital cancers and other lesions in the early 1980s.  In particular, they showed that HPV types 16 and 18 could be found both as free virus in cervical cell sample biopsies and integrated into the cell genomes of cell lines derived from cervical cancers.  A major finding in 1987 was that the legendary HeLa cell line – derived from a malignant cervical tumour from a Henrietta Lacks in 1951contains multiple copies of the HPV-18 genome.  The first HPV genome sequence (of type 1b) was obtained in 1982; the first genital type (6b, from condylomas) in 1983, and the first high-risk cancer virus (type 16) in 1985.

Later work involving large international surveys showed by 1995 that 99.7% of cervical cancers contained DNA from so-called “high risk” HPVs, leading to the conclusion that these were the necessary cause of cervical cancer, and that around 70% of these cancers were caused by HPVs 16 and 18.  Since then, HPVs have been found in more than 80% of anal cancers, 70% of vulval and 40% of vaginal cancers, around half of all penile cancers, and in roughly 20% of head and neck cancers.  If 16% of cancers are due to infection, and HPVs cause or are implicated in 30% of these, then they are a significant cause of cancers worldwide.

Harald zur Hausen was awarded a half share of the 2008 Nobel Prize in Physiology or Medicinefor his discovery of human papilloma viruses [sic] causing cervical cancer”.  I blogged on this at the time, here.

Work on vaccines against papillomaviruses (PVs) started early, after demonstrations presumably in the 1930s that domestic rabbits inoculated with the cottontail rabbit PV (CRPV) could become immune to reinoculation after recovery, and in 1962 that a “…formalin-treated suspension of bovine papilloma tissue” provided protection against challenge, but was not therapeutic.  However, progress was stymied by the fact that it proved impossible to culture any of the PVs, and challenge material had to be made from infected animal tissue, even though it had been shown that isolated viral DNA was infectious.

This changed after the advent of molecular cloning, when whole viral genomes could be prepared in bacteria.  Model systems for use in PV vaccine research by 1986 included cattle and bovine PVs, rabbits and CRPV and rabbit oral PV, and dogs and canine oral PV.  It had also been demonstrated that the L1 major structural protein of type 1 BPV produced in recombinant bacteria was protective against viral challenge in calves.  Jarrett and colleagues demonstrated, in 1991 and 1993 respectively, that they had achieved prophylactic and therapeutic immunisation against cutaneous (ie: skin; caused by BPV-2) and then mucosal (respiratory tract; BPV-4) bovine PVs, using E coli-produced proteins.  L1 and L2 proteins were protective against BPV-2, while L2 was protective against BPV-4 infection.  They suggested BPV-4 was a good model for HPV-16 given its mucosal tropism.

By the early 1990s several groups had demonstrated that it was possible to make PV virus-like particles (VLPs) by expression in eukaryotic systems such as yeast or animal cells of the L1 major virion protein either alone, or together with the minor protein L2.  In 1991 Ian Frazer’s group showed that expression of HPV-16 L1 and L2 together but not separately in animal cells via recombinant vaccinia virus, resulted in 40 nm particles resembling the virion being made.  In 1992 John Schiller’s lab showed VLP formation by L1 alone, with both BPV-1 and HPV-16 L1 genes expressed in insect cells via a baculovirus vector. In 1993 came the demonstration that expression of the plantar wart-causing HPV-1 L1 gene alone and L1 and L2 genes together in animal cells via vaccinia virus, as well as of the genital wart-causing HPV-11 L1 expressed in insect cells, resulted in VLP formation.  By 1995, it had been shown that immunisation of rabbits with CRPV L1-only or L1+L2 VLPs, and of dogs with canine oral PV L1 VLPs, protected completely against viral challenge.

hpv vlps

This groundwork made it possible for Merck and GlaxoSmithKline to develop and to push through to human trial and licensure, two independent VLP-based vaccines.  Merck’s vaccine – Gardasil – is quadrivalent, consisting of a mixture of VLPs made in recombinant yeasts from expression of L1 genes of HPV types 6 and 11, to protect against genital warts, and types 16 and 18, for cervical lesions and cancer.  GSK’s offering – Cervarix – is a bivalent HPV-16 and -18 vaccine only, consisting of VLPs made via recombinant baculoviruses in insect cell culture.  These are only the second anti-cancer vaccines on offer, and have gone on to blockbuster status within months of their release: Gardasil was licenced in June 2006, and Cervarix in October 2009.

Both appear to protect very well against infection with the types specified, but not to affect established infections.  Their long-term efficacy against cervical cancer is still to be established, although Gardasil has certainly lessened the incidence of genital warts in Australia post introduction in 2007.  There is now also a VLP-based vaccine for canine oral PV.

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