From The Guardian: Should boys be vaccinated against the human papilloma virus?

Deciding which HPV vaccine – if any – to use in a specific country requires financial, social and cultural considerations. My most recent blog post on The Guardian Science Blog discusses the question whether men should also be vaccinated against the virus.

A recent study has shown that most British doctors would give Gardasil to their own daughters – but the same question was not asked regarding their sons.

I provided information about cancers other than the cervix, which are also linked to the human papillomavirus – and which often occur in men, such as anal cancer.

Another question to consider is what can be done to protect homosexual men, given that they don’t benefit from the herd immunity acquired by vaccinated women.

Finally, I write about the effect that sexual behaviour has on HPV infections.

You can find the story here. Have you done any research on this topic? Please add your knowledge to this discussion.

From The Guardian: How do you choose the best vaccination against cervical cancer?

My thoughts on the balance between both HPV vaccines have been published on The Guardian Science Blog.

I wrote about the relevance of genital warts in young people and how the choice of a vaccine could have a cultural dimension.

I also clarified why the UK Government didn’t follow the recommendations made by the Joint Committee on Vaccination and Immunisation (JCVI) to adopt the Gardasil vaccine, going for Cervarix instead.

Once you read it here, I challenge you to come back and share a comment!

Anne Szarewski

Men at “increased risk” of HPV

When I interviewed Dr Anne Szarewski, a clinical consultant at Cancer Research UK, she raised interesting points with regards to the effect that HPV has on men. Ideally, she would vaccinate all the boys with Gardasil and all the girls with Cervarix. Listen to this bit of our interview to find out how and why.

Audio transcript
Anne Szarewski – I’ve always been extremely in favour of vaccinating men for so many reasons. First of all I think on a public health equality basis I think it’s almost outrageous that we actually put all the burden as though it’s only women who transmit a sexually transmitted virus. On a public health message that is just wrong. Secondly, if we don’t vaccinate men then of course the men who have sex with men get nothing because they cannot benefit from the immunity from women, that’s impossible. So we just ignore them. Of course they are at increased risk: anal cancer, penile cancer, genital warts (obviously for them you would use Gardasil I’ve never suggested using anything other than Gardasil for men). I really do believe we should be vaccinating both. And of course now that the evidence is getting stronger for head and neck cancers, all these non-genital cancers associated with HPV, then again the message gets stronger to vaccinate men.

Débora Miranda – But as it is now your position is that the priority should be vaccinating women with Cervarix.

AS – I would not be averse – and I think it could be done – that we could actually vaccinate all the girls with Cervarix and all the boys with Gardasil. I don’t think this is impossible. What would I think then need to be done is they would need to come to an agreement that probably you would stretch the Cervarix schedule to make that 0, 2 and 6 months. I suspect that the Cervarix schedule (it would have to be done in agreement with the companies and everything), but I suspect that the Cervarix schedule could be stretched to become 0, 2 and 6 months so that it would be in line with the Gardasil schedule – and then you would not have a problem of the girls being vaccinated at a different time to the boys. So you would have to make a change, but I think that would be a change that was worth doing. And you wouldn’t mess up the follow-up of the girls because they would still be getting Cervarix.

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UK: Cervarix is cost-effective

Yesterday, The Guardian Science Blog has helped me launch the debate on HPV vaccination. There you can read a blog post on my first findinds and thoughts.

In the past weeks I’ve come across very interesting studies about the two vaccines that can prevent cervical cancer.

First of all, in this Cancer Research UK’s page you can read very clear information about the human papillomavirus.

Secondly, it is worth reminding the main differences between the two vaccines.

1 – Cervarix:

2 – Gardasil:

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Just a few days ago, the Department of Health has responded to my Freedom of Information (FOI) request. My main questions were related to the scientific evidence that led the UK Government to choose Cervarix over Gardasil. They clearly admitted that the Joint Committee on Vaccination and Immunisation (JCVI) recommended the use of Gardasil as it protects against not only cervical cancer but also genital warts, so the decision was ultimately determined by matters of cost-effectiveness. We all would like to know how much the UK has paid for the vaccine, neverhteless the FOI response stated that:

The information in question has been identified at all stages as being commercially sensitive and we have considered your request very carefully, taking account of all the circumstances.  In short, as explained below, we have reached the conclusion that the information you have requested should be withheld as exempt under FOIA section 43(2) which is available to protect commercial interests.

Now with the help of Dr Peter English, who is editor of Vaccines in Practice magazine and has been a consultant on vaccine boards for various vaccine manufacturers, I found out that the scientific evidence is not yet enough to permit any manufacturer to make claims of duration of efficacy beyond that which has been proved. One should not forget that such HPV vaccination programmes have been implemented a few years ago only, so we need to wait and remain monitoring the effectiveness of the programmes in order to draw conclusions.

One other thing I found out is that scientific evidence released after the UK Government went for Cervarix is that this GSK vaccine may offer cross-protection to other cancer-causing HPV strains that Gardasil doesn’t. Check out this study:

Human Papillomavirus (HPV) Vaccines: Limited Cross-Protection against Additional HPV Types, published in The Journal of Infectious Diseases

Gardasil and Cervarix
As you can see from this table, Cervarix offers cross-protection to HPV 45, which according to this study should be given priority in cancer prevention.

In addition, there are other worth mentioning aspects raised by Dr Peter English. Please note that these are his own opinions and not those of his employer.

Cervarix and immunity

Cervarix, which only contains the two oncogenic types, also contains an “adjuvant” – a chemical which makes the vaccine stimulate a higher level of immunity. GSK, who make Cervarix, claim that this means that the vaccine generates a stronger immune response, with more antibodies produced (a higher concentration of antibodies to the vacine in the blood stream – “higher serum levels”). As serum levels fall gradually over time, they suggest that this means that people given Cervarix will have immunity that will last for longer.

Gardasil, by contrast, while it protects against genital warts, is unadjuvanted. The antibody levels it generates are not as high as following Cervarix. Sanofi Pasteur Merieux, who make (or market) Gardasil in Europe claim that the levels are sufficient to give good immunity that is likely to last as long as it’s needed.

Are three doses necessary?

If antibody levels continue to fall as the graphs – and experience with other vaccines etc. – suggest, both vaccines are likely to provide protection for 10-25 years – but it’s hard to know for how much longer than Gardasil Cervarix will actually protect women. A single booster dose years after the original course could be expected to push antibody levels back up to the levels they were at after initial course of vaccine; and with the quantity of vaccine that is being produced for world-wide use, it’s likely that the cost will be considerably lower in 15 years time.

Have you found this interesting? Have you got any information that may be relevant to the investigation? I am particularly interested in knowing which countries use which vaccine in their (perhaps non existing) vaccination programmes. We know that both vaccines have been approved in most countries, but which one do their governments pay for – and which one does private care tend to go for?

I’ve received many emails and tweets so far. They all have been very useful in my research. Please contribute as well by commenting this blog post!

Anne Szarewski

Changing vaccines: a ‘foolish decision’

As I mentioned before, there are two vaccines for the ‘cervical cancer’ virus, HPV – Cervarix and Gardasil. But why do some countries choose one over the other? And how do these decisions get made?

As you can see from this cervical cancer research timeline, studies about a possible HPV vaccine started in the 1990s.

In the UK, once the vaccines were proven safe and effective, the Joint Committee on Vaccination and Immunisation looked at the evidence and made its recommendation to the Department of Health in 2008. As a result, the government decided to use Cervarix in their screening programme. But following a debate on whether the NHS should replace Cervarix with Gardasil, it seems that the committee might have to go through the whole long-winded procedure all over again.

To find out more about what should happen next, I spoke to Dr Anne Szarewski – a clinical consultant at Cancer Research UK’s Centre for Epidemiology, Mathematics and Statistics at the Wolfson Institute of Preventive Medicine.

You can listen to our conversation below – but these are the main issues that Dr Szarewski raised:

Given that the vaccination programme is only just being rolled out, switching now would prevent us from comparing the effectiveness of each of the vaccines. Therefore, “the government would be foolish to change at this point”.

Similarly, a country needs to decide whether it is more important to prevent cervical cancer with a greater protection or to prevent genital warts and cervical cancer with less protection for the latter. “Cervarix offers much greater protection against cervical cancer than Gardasil does because it has a lot of cross-protection against other high-risk HPV types that are actually not included in the vaccine,” says the expert.

There are countries where culture and religion affect this decision. As Dr Szarewski says, “what’s going to work for example in a Muslim society is not likely to be the same in ours.”

Therefore, she believes Cervarix tends to be more popular in conservative countries. Vaccinating a woman against a sexually transmitted disease in those countries is “alien”, says the expert. Why would you vaccinate women against genital warts when they are supposed to have one sex partner their entire life?

Additionally, a country’s infrastructure determines the effectiveness of a vaccination programme. Without good transport and call-recall systems, which ensure that girls are given the jabs at the right time, women will not be looked after appropriately.

And finally, “the pharma industry of course is involved but ultimately it is the Department of Health that has to make the decision.”

Vaccination_of_girl

Understanding policy over vaccination

The fight against cervical cancer can begin as early as the age of 12.

In September 2008, the UK National Health Service (NHS) started a national programme to vaccinate girls aged 12 to 13 against the human papillomavirus (HPV).

But the UK is just one example of how the discovery of a vaccine leads to a national vaccination programme. In fact, not all countries have invested in one. Those who did, may not have chosen the same vaccine. And also the way vaccination programmes are designed can differ – concerning the age vaccines are taken, the price paid by the governments and whether all those covered by the programme actually have access to the vaccine.

There are two vaccines that can protect against cervical cancer: Gardasil and Cervarix.

The Gardasil vaccine was created by German pharma company Merck, and was first approved by the US Food and Drug Administration (FDA) in 2006. Although it does not prevent all types of cervical cancer, Gardasil protects against four types of HPV: two of them (16 and 18) cause most of cervical cancer cases; the other two (6 and 11) are responsible for 90 per cent of genital warts cases. It is given as three injections over six months (if starting in January, the second would be given in March and the third in June).

The Cervarix vaccine was created by the UK’s GlaxoSmithKline (GSK) and licensed by the European Medicines Agency (EMEA) for use in the UK in 2007. Cervarix protects against HPV types 16 and 18. Like Gardasil, it is given as three injections over six months, but in different times (if starting in January, the second and third ones would be given in February and June respectively).

Nevertheless, this brief description of both vaccines is not enough to judge the effectiveness of each one nor the reasons that lead certain countries to choose one or the other. Some issues should be considered when comparing both vaccines:

– HPV is not only responsible for cervical cancer, but also for other types of cancer (such as neck, anal, penal, head) as well as genital warts;

– Being a sexually transmitted virus, HPV is a taboo in rather conservative countries;

– A vaccination programme is only effective with an effective calling system (i.e every person covered by the programme receives an invitation) to ensure that the three vaccine doses are taken appropriately;

– Vaccinating girls will affect how often they need cervical screening later in life, so the information given to both children and parents needs to be clear and accurate;

–  Although the evidence on vaccinating young girls is relatively clear-cut, research has not yet shown whether the uptake of the vaccine by young adults is effective, appropriate, cost-effective – or even harmful.

You can find more information on HPV vaccines here.

Cancer experts have kindly agreed to talk to me about some of these issues and I will soon be sharing their thoughts here. In the meantime, please feel free to share your experiences and doubts. The same experts might be able to answer your questions. How much is known about the vaccination of cervical cancer in your country?