It’s exciting to have people vaccinated at the rate – more than 150,000 doses were administered in Utah last week, and the number is expected to rise first. On April 1, all adults can enroll in Utah, but for some, the decision is not that easy.
Children, pregnant women and those who have had COVID-19 can face different challenges. I want to explain why this is, and what science says about the vaccination options for these groups.
Vaccinations for children
Teens 16 years and older can receive the Pfizer vaccine, but not Moderna or Johnson & Johnson. For those under 16, we are still waiting for clinical trials.
As with everything COVID-19 and children, it is important not to think of children as one group, but as different age categories. In many ways, adolescents who have gone through puberty appear to have outcomes similar to – though better than – other young adults, while children younger than them have additional protective abilities that make the symptomatic infection less likely.
So these companies have been testing their coronavirus vaccines in teens for months. Moderna’s “TeenCove” study, which began in December, aims to study the impact of the vaccine in about 3,000 12-18-year-olds. Pfizer’s vaccine was initially tested at the age of 16 and older, and the company completed a study on 12-15-year-olds in January.
Biologists have great confidence that the vaccine will actually work the same in these teens as in older people, but we obviously need to study it to make sure. The results of these studies are expected to be announced “mid-year 2021. ″ It appears that the researchers are trying to reach conclusions before the school year 2021-22, so June or July is a relatively safe bet.
And now we are also studying the vaccine in younger children. Moderna announced on Tuesday a phase 2/3 study to test the vaccine in two different age groups: six months to two years old and two years to 12 years old. Researchers will test the vaccine on 6,750 children and experiment with different dose sizes to see which one is the best. On the younger set they give quarter, half and full size doses, and on the older set they will try both the half and full doses. Pfizer has not yet begun a similar study, but says it plans to do so this month.
When will we get the results of these trials? “If we just look at the timelines, it’s probably the end of 2021 to early 2022 for younger children, but maybe it’s going a little faster than that,” said Robert Frenck, director of the vaccination research center at Cincinnati Children’s Hospital and a lead researcher for Pfizer’s research, told Bloomberg.
The Johnson & Johnson vaccine is interesting when it comes to children, not only for the simplicity of one dose, but also because it uses an older vaccine technology. This means that vaccines of its kind have already been used on young children, also for Ebola and RSV. While Johnson & Johnson has not yet begun a study among young people under 12, they are planning to.
Vaccinations for pregnant women
The Centers for Disease Control and Prevention does not directly recommend that pregnant mothers be vaccinated, but it does not say that they should not do so. These federal officials say it is a ‘personal choice’. This is because the vaccines were not originally tested on pregnant women, but all the signs so far have been positive.
The vaccination trials for Pfizer, Moderna and Johnson & Johnson generally excluded pregnant women, but a few slipped through – women who did not know they were pregnant, or became pregnant after the trial began. A total of 18 pregnant women were “accidentally” vaccinated as part of these trials, and no one experienced adverse effects.
More recently, the CDC followed 30,000 pregnant women who chose to be vaccinated, including 1,800 who agreed to give detailed descriptions of their outcomes. As Harvard Medical School reports: “So far, pregnant people seem to have the same side effects as non-pregnant individuals. No miscarriages, stillbirths or premature births related to the vaccines were reported. ”
More invasive tests have also been done in pregnant animals with the coronavirus vaccination. No red flags were raised again.
In particular, it does not appear that the vaccine itself – or the mRNA particles in the Pfizer / Moderna vaccines or the modified virus of Johnson & Johnson’s vaccine – eventually reaches the placenta. It is absorbed relatively quickly by the body.
What does appear is that after the antibodies are developed in response to the vaccine, those antibodies are shared with the baby. A Massachusetts General Hospital study in which 10 newborns’ umbilical cord blood was tested after their mothers were vaccinated found antibodies in all 10. A similar study in Israel found the same, but with 20 women / newborn couples.
This is not a big surprise, this is what happens with most vaccinations. But this is basically the best case: newborns have a relatively high risk with respect to COVID-19, and it appears that vaccination of the mother can give antibodies to the babies without exposing them to the vaccine injection.
Meanwhile, Pfizer does have a trial underway with 4,000 expectant mothers, the first participants of which were dosed about a month ago. After the trial is complete in a few months, I expect the CDC to give it its full chance.
Vaccinations for those previously infected with COVID-19
Currently in Utah, those infected with COVID-19 over the past 90 days are being asked to wait to be vaccinated. The reasoning is simple: you already have the antibodies and are currently strong, so save the dose for someone else.
That said, the Utah decision is a proposition – if you really want to get vaccinated, even though you’ve been infected for the past 90 days, you can do so. It’s a kind of selfish move, but sure.
Interestingly, studies show that those who are already infected tend to have a stronger immune response to the first dose than those who have not yet had COVID-19.
And in fact, there are now several studies showing that just one dose should be sufficient for full protection for those who have already had the disease. These studies show 100x to 1000x multiplication in antibody levels after the first dose, but no actual change in antibodies after the second dose.
It makes sense. For ‘naive’ individuals of COVID-19 – people who are not infected – the first dose teaches the body about the virus, and the second teaches the body that the virus is a constant threat. For those who are already infected, the first dose serves as the lesson. A second dose is just too much: “Puppy, here’s this virus for the third time this year.”
Those who have already had the coronavirus should definitely be vaccinated eventually, but maybe not multiple times. The current CDC and Utah protocol is to give these individuals both doses, although scientists working on the above studies have made a petition to the CDC to change it. It takes a lot for the CDC to change its mind, which is reasonable, though reasonable, but some other countries have dropped it all at once.
If I had been infected before, my approach would be ‘wait and see’. If I had tested positive for the past 90 days, I would have waited for my dose so that someone at higher risk could get it. If it was longer than that, I would get my first dose ASAP and then use the next 21-28 days to look at the CDC’s page for changes in their protocol.
Andy Larsen is a data columnist. He is also one of The Salt Lake Tribune’s Utah Jazz beat writers. You can reach him at [email protected].