It’s exciting that people are getting vaccinated at the rate we have: more than 150,000 doses were administered in Utah last week and that number is only expected to increase. On April 1, all Utah adults can sign up, but for some the decision is not that easy.
Children, pregnant women, and those who have had COVID-19 may face different challenges. I want to explain why this is and what science says about vaccination options for these groups.
Vaccines for children
Adolescents 16 years of age or older may receive the Pfizer vaccine, but neither Moderna nor Johnson & Johnson. For those under 16, we are still awaiting clinical trials.
As with all COVID-19s and children, it is important not to think of children as a group, but of various age categories. In many ways, adolescents who have gone through puberty appear to have results similar to, though better than, other young adults, while children younger than this appear to have additional protective abilities that make the symptomatic infection more unlikely.
Thus, for months, these companies have been testing their coronavirus vaccines in adolescents. Moderna’s “TeenCove” study, launched in December, seeks to study the impact of the vaccine on about 3,000 children ages 12 to 18. The Pfizer vaccine was initially tested from the age of 16 and the company fully enrolled a study in children aged 12 to 15 in January.
Biologists are very confident that the vaccine will work essentially the same in these teens as in the elderly, but of course we need to study it to make sure. The results of these studies are expected to be published in mid-2021. Researchers appear to be trying to draw conclusions before the 2021-22 school year, so June or July is a relatively safe bet.
And now, we are also studying the vaccine in younger children. Moderna on Tuesday announced a phase 2/3 study to test its vaccine in two different age groups: six to two years old and two to 12 years old. Researchers will test the vaccine on 6,750 children and experiment with different dose sizes to see which is the most effective. In the younger group, they will give quarter, medium, and full-size doses, and in the older group, they will test medium and full doses. Pfizer has not yet begun a similar study, but they say it is scheduled for this month.
When will we get the results of these tests? “Just looking at the timelines, it’s likely to be more likely to end in 2021 in early 2022 for younger children, but maybe it will go a little faster than that,” said Robert Frenck, director of the Research Center. of Cincinnati Children’s Hospital Vaccine and principal investigator of Pfizer research, told Bloomberg.
The Johnson & Johnson vaccine is interesting when it comes to children, not only because of the simplicity of a single dose, but also because it uses ancient vaccine technology. This means that such vaccines have already been used in young children, including against Ebola and RSV. Although Johnson & Johnson has not yet begun a study on children under 12, it plans to do so.
Vaccines for pregnant women
The Centers for Disease Control and Prevention does not fully recommend that pregnant mothers be vaccinated, but neither does it say they should not. These federal officials say it’s a “personal choice.” This is because the vaccines were not originally tested in pregnant women, but all the signs so far have been positive.
Vaccination trials against Pfizer, Moderna, and Johnson & Johnson generally excluded pregnant women, but some escaped: women who did not know they were pregnant or who became pregnant after the trial began. A total of 18 pregnant women were vaccinated “incidentally” as part of these trials, and none experienced adverse effects.
More recently, the CDC has followed 30,000 pregnant women who chose to get vaccinated, including 1,800 who agreed to provide detailed descriptions of their findings. According to Harvard Medical School, “so far pregnant people appear to have the same vaccine side effects as non-pregnant people. No abortions, stillbirths or vaccine-related premature births have been reported.
More invasive tests have also been performed in pregnant animals with coronavirus vaccines. Again, no red flags were raised.
In particular, neither the vaccine itself appears, nor the mRNA particles from the Pfizer / Moderna vaccines nor the modified Johnson & Johnson vaccine virus, end up reaching the placenta. These are dragged by the body relatively quickly.
What seems to happen, however, is that after the body develops antibodies in response to the vaccine, those antibodies are shared with the baby. A Massachusetts General Hospital study that tested the umbilical cord blood of 10 newborns after vaccinating their mothers found antibodies in all 10. A similar study in Israel found the same, but with 20 pairs of women / newborns.
This is not a big surprise, it is what happens with most vaccines. But it’s basically the best case scenario: babies have had a relatively high risk for COVID-19, and it seems that vaccinating the mother can give antibodies to these babies without exposing them to the same vaccine injection.
Meanwhile, Pfizer is running a trial with 4,000 expectant mothers, and the first participants were dosed about a month ago. After this trial ends in a few months, I hope CDC will give its full approval.
Vaccines for those previously infected with COVID-19
Right now, in Utah, those who have been infected with COVID-19 for the past 90 days are being asked to wait to be vaccinated. The reason is simple: you already have the antibodies and they are currently strong, so save the dose for someone else.
That said, the Utah decree is a suggestion: if you really want to get vaccinated despite being infected in the last 90 days, you can. He’s kind of selfish, but sure.
Interestingly, studies show that those who have already been infected tend to have a stronger immune response to the first dose than those who have not had COVID-19.
And, in fact, there are now several studies showing that just one dose should be enough for complete protection for those who have already had the disease. These studies show a 100x to 1000x multiplication in antibody levels after the first dose, but no actual changes in antibodies after reaching the second dose.
Does that make sense. For “naive” people with COVID-19, people who have not been infected, the first dose teaches the body about the virus and the second teaches the body that the virus is an ongoing threat. For those who have already been infected, this first dose acts as this lesson. A second dose is too large: “Welp, here’s this virus for the third time this year.”
Therefore, those who have already had coronavirus should be vaccinated permanently, but perhaps not several times. Still, the current CDC and Utah protocol is to give these people two doses, even though the scientists who worked on the previous studies have asked the CDC to change that. It takes a long time for the CDC to change its mind, which is reasonable, though reasonable, but some other countries have already put it aside.
If I had been infected before, my approach would be “wait and see”. If I had tested positive in the last 90 days, I would have waited for my dose so that someone at higher risk could get it. If more time had passed, I would get my first dose as soon as possible, and then use the next 21-28 days to view the CDC page to see changes to its protocol.
Andy Larsen is a data columnist. He is also one of the Utah Jazz beat writers for The Salt Lake Tribune. You can get there at [email protected].