💉 The other vaccine shortage that kills 300k poor women a year 👧🏾
Why vaccine mandates for s*x workers could be the next thing
Hello and welcome to Careviser, the weekly newsletter that cuts through the healthcare noise with a single focus: productization of the latest research and tech breakthroughs.
By now, we have all become experts in covid-19 vaccines. There’s a lot of outrage because, despite many promises by rich countries, we haven’t given enough doses to low-income countries. As covid-19 vaccines are about to be cleared for kids in the US, we tend to forget that there is another vaccine that would benefit young girls: the HPV vaccine. And low-income countries face a shortage of that vaccine too.
When the HPV vaccine launched, its effectiveness was debated (as cervical cancer sometimes starts decades after a patient was vaccinated). It’s now proven to be effective in the long run, though there is still debate about whether a booster dose could be needed at some stage.
Optimal human papillomavirus vaccination strategies to prevent cervical cancer in low-income and middle-income countries in the context of limited resources: a mathematical modelling analysis, Mélanie Drolet, Jean-François Laprise, Dave Martin, Mark Jit, Élodie Bénard, Guillaume Gingras, Marie-Claude Boily, Michel Alary, Iacopo Baussano, Raymond Hutubessy, Marc Brisson,The Lancet Infectious Diseases, 2021
🗝️ Why it matters: The vast majority (80%) of cervical cancers occur in low to middle-income countries due to lack of access to HPV vaccines. Cervical cancer kills 300,000 women a year. The World Health Organization aims to eliminate cervical cancer, which is a preventable disease thanks to highly effective vaccines.
🔎 The study: Low and middle-income countries have limited access to doses of vaccines as there face both supply and financial constraints. They need to optimize their vaccination strategy according to these constraints around the following parameters:
Should they vaccinate only girls or boys and girls?
What age cohort should they focus on? Should they try to catch up on older patients that haven’t been vaccinated yet?
How many doses and at what interval should they be administered?
So far existing modeling studies focused on vaccinating multiple-age cohorts of girls. The authors aimed to present new modeling options that take into account all the parameters at stake along with realistic assumptions on sexual behaviors and infections (including for instance sex workers and their clients that have been identified as bridge populations for transmission leading me to wonder if mandatory vaccination of sex workers could be on the table?)
✅ Findings: The author created the modeling analysis based on 4 countries (India, Vietnam, Uganda, and Nigeria) that exhibit very different sexual behavior, HPV, and cervical cancer prevalence. They compared 7 vaccination scenarios for each country.
They found that vaccination of girls aged 9 years would decrease the incidence of cervical cancer by between 79-85% effectiveness depending on the country. Vaccinating girls aged 14 years would accelerate the decrease in incidence but lead to a slightly slower decrease of incidence in the long run (1 to 4% less).
The most efficient strategy (if using two doses of vaccine) was a routine vaccination of girls aged 9 to 14 either by vaccinating girls who are 13 or 14, or girls who are 9 or 10 with several years between each dose. In case of additional doses, it would be best to extend vaccination to older cohorts of girls as opposed to vaccinating boys. In Asian countries that would lead to the elimination of cervical cancer, when other countries would require additional policies such as HPV screening tests.
🚀 Opportunities ahead: The modeling results of these studies were presented to the WHO in 2019 and helped inform their global HPV vaccination policy recommendations. This study is fascinating and I recommend anyone interested in health policy data science to read it as the authors go deep in the details of every single assumption (50 parameters in total) they used for the modeling analysis.
Vaccitech is an exciting clinical-stage biotech company founded in 2016 as a spin-off from Oxford University. They are well-known as the co-inventors of the covid-19 vaccine licensed to AstraZeneca by the University of Oxford. Vaccitech is entitled to 24% of payments received by the University of Oxford from AstraZeneca for the commercialization of the vaccine (about 1.4% of AstraZeneca net sales). However, since the University of Oxford decided to forego any payment claims related to the covid-19 vaccine until the pandemic ends, they are not likely to make any money from this agreement in the near future.
They ipo’ed this year following a successful Series B round. I highly recommend reading their S-1 if you’re interested in learning more. They have a great pipeline of therapeutics, including one focused on HPV infections:
🤯 The problem: The vast majority of cervical cancers are caused by HPV infections. When these HPV infections are persistent over time, they may cause cervical precancerous lesions. Currently, these lesions can only be cured with invasive interventions such as cryoablation. HPV vaccines are highly effective at preventing cervical cancer, however, only women born after 1991 have benefited from them, and even in some rich countries, there is low adoption of vaccination (only 30% in France for instance!).
🤗 The solution: Vaccitech is developing a non-invasive treatment for high-risk HPV infections.
📈 The traction: Vaccitech HPV treatment was well tolerated in preclinical animal studies. They have now moved on to a phase 1/2a clinical study with 105 women. The interim results will be published in Q1 2022.
Regarding Vaccitech’s strategy, they aim to retain full control and ownership of their upcoming therapeutics, contrary to what they did with the covid-19 vaccine. I guess that given how fast they had to act in the face of the covid-19 pandemic, they had no choice but to partner with a large company such as AstraZeneca that would optimize the probability of actually bringing the vaccine to the market.
That’s a wrap for today! Don’t hesitate to reply to this email with comments, I read and answer all emails :)
Marie