For half a century, Gurusaran Pran Talwar has been developing the next big thing in contraception. The 90-something former director of India’s National Institute of Immunology envisions bringing to market a new form of birth control that can prevent pregnancies without the usual trade-offs. Inexpensive, discreet and easy to manage. Less invasive than intrauterine devices and more convenient than daily pills. That way, you’ll avoid nasty and sometimes dangerous side effects like weight gain, mood swings, and the rare but dangerous blood clots and strokes. It embodies something of a “set it and forget it” model that has become the golden rule of health, and will, in his words, be “accepted all over the world.”
Talwar’s invention is currently in early stage clinical trials. If all goes well, this could be humanity’s first contraceptive vaccine, and one that prevents pregnancy in a way unlike any contraceptive ever approved for human use. Whether packaged as tablets, patches, implants, or shots, most common medical contraceptives work by injecting hormones into your body to pause ovulation. Talwar’s vaccine will do something different. It doesn’t alter the menstrual cycle, but instead harnesses the power of the immune system to prevent unwanted pregnancies.
But temporary vaccination against pregnancy, both scientifically and socially, is a brilliant concept but devilishly difficult to implement. Making a contraceptive vaccine essentially means “trying to immunize an animal against itself,” said an expert in feline infectious diseases at the University of Florida who has been working on animal immune contraceptives. says Julie Levy. This goes against the primary directive of the immune system, which has evolved over countless millennia to distinguish between foreign and familiar, leaving the body’s most vital tissues untouched. Solving this problem leaves researchers with another challenge. It’s about convincing people to get fertility-killing vaccines in an era of vaccination reluctance, when past fears of contraceptive issues still linger.
For decades, the most stubborn barriers in contraception were not about science, but about access and acceptance of contraception. Talwar said that she encountered several groups of women in the holy city of Varanasi in the 1970s and struggled to support a large family. She remembers, she said. However, the women’s husbands were reluctant to use condoms, and they themselves were dissatisfied with the pills and IUDs available at the time. These sometimes interfered with normal menstruation and ovulation, and sometimes caused headaches and mood swings. “I wanted to create something free from all these problems,” Talwar told me.
Within a few years, he had worked out a solution. It was a vaccine against hCG, the pregnancy-specific hormone needed for the implantation of a fertilized egg. Talwar reasoned that the immune system, which has been taught to neutralize hCG, could prevent pregnancy from taking off without attacking other tissues. His premonitions so far seem to have come true. By the mid-1990s, his team found that, in small, early-stage clinical trials, most vaccinated women produced enough antibodies to prevent pregnancy for months, sometimes a year or longer. showed what it can do. Of the 119 women in the trial, those whose antibody levels reached what Talwar considered a protective threshold were: only one pregnant for almost two years. Some participants continued to become pregnant after opting out of the boosters, indicating that the effects of the injections are reversible.
almost immediately, but shortcomings appeared. Immune responses are known to vary from person to person. This is the main reason why the effectiveness of many vaccinations against pathogens reaches about 60-80 percent. About one-fifth of women who received the hCG vaccine did not develop enough antibodies to meet the protective threshold. These statistics would be enough to slow the spread of deadly respiratory viruses, for example. But expectations for contraceptives “should be different,” said Neil Shah, chief medical officer at Maven Clinic, a virtual clinic for women’s and family health. Her IUD, one of the top on the market, prevents over 99 percent of pregnancies, requires her one appointment for insertion, and lasts up to 10 years.
For now, the hCG vaccine is more troublesome than that. Current iterative methods (improvements on successful recipes of the 90’s) require an initial series of at least three doses separated by several weeks. Without routine antibody testing, it is still unclear how people will decide when and how often to boost. The answer probably varies from person to person. Diana Bryce, a contraceptive expert at the National Institutes of Health, said the uncertainty alone could make it difficult to market the vaccine. She also said that stopping hormonal contraceptives can reset fertility to baseline within days or weeks, although some people with particularly enthusiastic immune responses may eventually die. I have. waiting so long Aaron Xue, a reproductive biologist at Stanford University, said the hCG vaccine could be less effective. For that and other reasons, Shwe has long said he was “not very enthusiastic” about Talwar’s experimental shots.
There are several reasons to believe that these problems are not insurmountable. Immunocontraceptives have been used to: decades by wildlife scientists prevent pregnancy of mammals of all kinds—These include deer, horses, elephants, pigs and seals as a more humane alternative to culling. And in that situation, at least researchers have found a way around the need for frequent boosts. certain animals are administered nanoparticles or slowly release vaccine components It tickles the immune system repeatedly without additional attacks for months or years, says Derek Rosenfield, a veterinarian and wildlife biologist at the University of Sao Paulo. But studies in wildlife show how difficult it is to persuade the body to target its own hormones. In order for vaccines to be effective, veterinarians must include powerful adjuvants, or vaccine components, that activate the immune system, and “there are some of the most powerful ever developed. ‘” Levi told me. A tax will be imposed on the efficacy of vaccination. In some animals, such as cats, vaccines can cause worrying side effects, such as injection site reactions.
Talwar’s hCG vaccine also faces some problems with tolerability in humans, where stricter safety standards and improved efficacy are needed. So far, the side effects of pills and IUDs seem to have been avoided. But some of the women his team is taking part in ongoing trials have developed painful but noticeable nodules. This is a sign that the new recipe’s adjuvants may be stimulating the immune system a little too much. Achieving a discreet, low-maintenance contraceptive (“zero side effects,” as Talwar puts it) requires creative dosing and composition.
A gap in the contraceptive market needs to be filled. Technology has come a long way since Talwar first spoke with the women of Varanasi, but “we need more options,” said Devanjana, director of programs and partnerships at the Reproductive Health Services Foundation of India. Chowdhury says Nearly half of all pregnancies worldwide are unplanned, and access to existing contraceptive methods is inconsistent, unfair, and still hampered by stigma and misinformation. Even where availability isn’t an issue, some are hesitant about tradeoffs. Temporary contraceptives packaged in ultra-safe vaccines may offer convenience and privacy, urban youth already addicted to injectable contraceptives and unconcerned about boosters Chowdhury said there is a potential attraction for Most importantly, adding a vaccine to the repertoire gives people an ‘alternative choice’.
However, while contraceptive vaccines have many benefits, they can also come with societal drawbacks. The history of birth control is riddled with abuse and is often concentrated in the poor, those suffering from mental health problems, and communities of color. For centuries, the main purpose of vaccines has been to fight infectious diseases and “pregnancy is not a disease,” said Sangamitra Singh, policy and program director at the Population Foundation of India. Even if unintentional, hinting that this symptom is a problem that needs to be eradicated can stigmatize the shot.
Distributing vaccines to primarily resource-poor populations could eradicate the fertility of the most vulnerable segments of society. Lisa Campo-Engelstein, a reproductive bioethicist at the University of Texas Medical School, worries that even the vaccine’s ease of administration—an ostensible advantage—may be viewed as a downside. Administering a vaccine without the patient’s full understanding and consent is easier than forcing it. Inserting an IUD or forcing a daily pill. And in this pandemic era, contraceptive vaccines are likely to face backlash from those already reluctant to vaccinate, especially amid false accusations that other vaccinations impair fertility. Moreover, post-hCG vaccination can only prevent implantation, not fertilization, a definite challenge for those who believe that life begins with conception, and that the vaccine will trigger abortion. Some might argue.
In a way, it was just bad timing. Already in his late 60s in his 90s, shortly after the first clinical trial results were published, Mr. Talwar was asked to retire from the National Institute of Immunology and had to leave vaccines behind. he told me. It took Indian regulators nearly a decade to greenlight a new recipe for clinical trials after he revived his efforts with the help of independent funders, just as the coronavirus pandemic hit. It was just about to begin. Regine Citruk Ware, a reproductive endocrinologist at the Population Council’s Center for Biomedical Research in New York, remembers the initial buzz around the human hCG vaccine when Talwar’s clinical trial results were announced. But with no further progress, she and other researchers have moved on, she told me. Many are now turning to long-acting reversible male contraceptive methods, several new forms of which are now nearing general availability, safely complementing women’s methods and helping families Potentially make the plan fairer.
Still, Talwar, who turns 97 in October, hasn’t lost hope. For him, the nodule is one of the last big hurdles for him and should be resolved soon. As his 100th birthday approaches, he wonders how he could expand his approach, even repurposing hCG shots for immunotherapy against certain cancers that produce hormones abnormally. there is “I am healthy and well,” he told me. “I just hope and pray” that his invention clears the final hurdle “before it ends,” he said.
