All of the coronavirus vaccines can save lives; take whichever you can get

At this critical juncture in the pandemic, it makes no sense to go shopping for vaccines as one might for shoes or breakfast cereal. The United States is fortunate to have a choice between the pair of twodose mRNA vaccines by Moderna and Pfizer/BioNTech, already given to tens of millions of people, and the one-shot Johnson & Johnson vaccine now being rolled out. All of them can save lives. Take whichever you can get.

At a time like this, when the virus variants are threatening a new surge of infections, the overriding goal must be to get as many people vaccinated as possible. The big picture is that all three vaccines have shown to be safe and efficacious in large clinical trials, and all three are believed to largely prevent hospitalizations and deaths from the virus. That’s a winning ticket for many people who might otherwise be stricken and face a lonely demise on a ventilator in a hospital ward.

All three vaccines are attempting the same biological conjuring trick: to instruct the body to generate spiky proteins like those on the coronavirus so the immune system will recognize and go after them when an infection occurs. The mRNA vaccines use a new technology to transmit the instructions by a bit of genetic material — messenger RNA — encased in a lipid, or fat. The Johnson & Johnson vaccine uses a traditional approach, ferrying the instructions on a deactivated bit of harmless cold virus. The Johnson & Johnson vaccine does not have the freezer requirements of the others, and the one-shot dose may be more convenient — and accessible — for many people.

The outcomes of Phase III clinical trials differed, but it would be wrong to base a decision on whether to get vaccinated just on these variations. The Food and Drug Administration adopted a standard that a vaccine must show greater than 50% efficacy for emergency-use authorization. For the first vaccines, that was measured against symptomatic illness because that was the fastest way to get a handle on results. A different endpoint, such as asymptomatic illness, hospitalization or death, might have delayed the clinical trials when time was of the essence. The Moderna and Pfizer vaccines scored 94.1% and 95% efficacy, respectively, against symptomatic illness after the second dose. This has been compared by some to the Johnson and Johnson trials in the United States, which showed efficacy of 72%. However, there were important variations in the trials and they really should not be matched head- to- head. The mRNA vaccines were tested earlier, and the Johnson & Johnson later, when variants had started to appear. The Johnson & Johnson trial endpoint was also somewhat different, including protection against severe illness.

Many questions about how well the vaccines work will only be answered with time, such as whether they can successfully block transmission of the virus or tackle the stealthy asymptomatic infections. But the bottom line is that any one of these three vaccines is a lifesaver worth grabbing when it is available.