So far, the covid vaccines are working out about as well as I had hoped for in my December 16, 2020 column “Let’s Be Over and Done in ’21.” We are now up to almost 55% of the population of age 16 and over having received at least one vaccine dose.
These vaccinations of 146 million people, along with the arrival of spring and the sizable share of Americans already infected by the end of the Third Wave of early winter, is paying off. Back in late March it looked like the U.S. might be heading into a Fourth Wave, but since mid-April that fear has fizzled, with cases dropping just about everywhere over the last two weeks except Oregon and Colorado.
Who knows what might happen in terms of weird mutations, but the trend looks good.
In the rest of the world, however, things aren’t going so well in countries with low levels of vaccination, such as India and Brazil.
Lately, I’ve been asked by several young people whether they should get vaccinated. Clearly, vaccines are a smart choice for oldsters like me, but how young do you have to be to make it, all in all, a better idea to skip getting vaccinated?
Here’s a new real world study of American hospitalizations due to covid among age 65+. There was concern when the impressive results of the clinical trials of the Pfizer and Moderna mRNA vaccines were announced last November that the vaccines wouldn’t work as well on older people because their immune systems are less hair-trigger. While the clinical trials did enroll people over 65, they were somewhat scare on the elderly. But now it looks as if both vaccines are great in the real world at keeping oldsters out of the hospital:
Among the 187 case-patients, 19 (10%) had received at least 1 dose of Pfizer-BioNTech or Moderna vaccine ≥14 days before illness onset (including 18 [10%] who were partially vaccinated and one [0.5%] who was fully vaccinated) compared with 62 (27%) of 230 test-negative controls (including 44 [19%] and 18 [8%] who were partially and fully vaccinated, respectively). Prevalence of receipt of Pfizer-BioNTech and Moderna vaccines was similar (53% and 47%, respectively, among those vaccinated with ≥1 doses). Adjusted VE [vaccine efficacy] for full vaccination using Pfizer-BioNTech or Moderna vaccine was 94% (95% CI = 49%–99%), and adjusted VE for partial vaccination was 64% (95% CI = 28%–82%) (Figure). There was no significant effect for receiving the first dose of a 2-dose COVID-19 vaccine series within 14 days before illness onset (adjusted VE = 3%, 95% CI = −94%–51%).
In other words, the vaccine efficacy of either the Pfizer or Moderna mRNA vaccines, when fully vaccinated, at keeping Americans at least 65 years of age out of the hospital for covid is a spectacular 94%, just like last year’s clinical trials found for vaccine efficacy at keeping people from developing symptomatic covid. In other words, you are only 6% as likely to wind up in the hospital if you get both doses of Pfizer or Moderna as if you get none.
On the other hand, you aren’t out of the woods yet after just one dose. After two weeks after the first dose but before the second dose, the vaccine efficacy is 64%: i.e., your chance of getting hospitalized for covid if you are at least two weeks out from your first dose but haven’t had your second dose yet is 36%, which is good but not as great as only 6% after the second dose.
Perhaps the mRNA vaccines’ efficacy of just one dose would grow given enough time, but my vague impression from the Israeli data is that the second dose really does help. This is not to say that Britain’s “first doses first” policy was not a clever idea. It may well have led to a more efficient allotment of doses under Winter 2021’s conditions of vaccine scarcity. But now that we have plenty of vaccines, it’s wise to get your second dose.
What about the very young? There are multiple considerations:
– One issue is risk to yourself from covid.
– Another issue is the risk you pose to others. Vaccines appear to somewhat reduce transmissibility of coronavirus, although the effect may not be as great as the self-protection effect. But it’s worth noting that if your local culture is encouraging you to be wary of getting vaccinated, you are probably more likely to infect somebody you know and like because they are also wary of getting vaccinated. So it makes sense to get vaccinated to protect the kind of people you like.