There are 2 major areas of interest in the Covid world right now – variants and vaccines. If you stop to think about the many and varied current pandemic problems, they can all be fairly easily fit into one of those 2 subject areas. During my last essay, I discussed variants, at least cursorily. Today, I think we should spend some time on where we now stand on vaccines.

Surprisingly, I am not going to spend much of my energy on the unvaccinated vs. vaccinated debate. I am just so tired of banging my head against that particular wall. To put it simply, if you are choosing at this point in time to refuse an effective vaccine against a devastating, highly contagious virus that is ravaging your country and the world, you are an idiot. The only exceptions are those few individuals with specific medical issues for whom the vaccine would represent an unreasonable health risk. The rest of you are just God damn selfish morons who are risking all of our safety to follow despicable “conservative” politicians and television talking heads. You deserve what’s heading your way, but the rest of us do not. (And someone told my brother the other day that I was too hard on the unvaccinated?? Where does that come from? I think I’m being pretty nice, considering.)

So, the big questions about vaccines right now concern their effectiveness. Are the vaccines losing their ability to keep us from being infected (hospitalized, killed)? Are the original vaccines still effective against the Delta variant? Will we need “booster” shots? If so, when and how often?

These are fair and important questions. The good news is that there is a lot of science being published right now that is providing data on which to base the answers for these questions. The bad news is that some of the data are conflicting. I’m sorry, but that’s the way science works. Well done, valid studies can arrive at different results and it can take some time for the science to settle out to a body of evidence on which public policy can be based. The public doesn’t like for the scientific community to appear unsure, but unfortunately that is the real world and CDC, WHO, and the FDA have to respond to the public’s concerns as the science continually shifts underneath their feet. As I’ve said previously, assessing and interpreting data in the middle of a pandemic is an unenviable task. You just have to be prepared to be wrong on some occasions.

When the Moderna and Pfizer vaccines were first announced last December, their effectiveness at reducing the risk of Covid infection was estimated to be approximately 95%. Reducing the risk of hospitalization and death was even higher. A scientific miracle certainly, but now people are wondering whether these levels drop significantly over time and whether we can expect the same level of protection from the Delta Covid variant as the shots awarded against previous variants.

For those of you who have not been paying attention, the Delta variant is of particular concern because Delta represents over 80% of the Covid infections in the US in July. Delta is 60% more transmissible than previous Covid infections and results in a viral load in infected individuals that is 1000 times more than prior variants. The unvaccinated are also twice as likely to be hospitalized with Delta than with previous Covid variants. From a public and personal health standpoint, we need to know just how effective our vaccines are against the Delta variant.

For this essay, I am going to summarize the large Mayo clinic study of vaccine effectiveness that should be published shortly. The researchers tested over 50,000 participants and found the Moderna vaccine was 86% effective against Covid infection and 92% effective against hospitalization for the entire study period. Pfizer was slightly less effective at 76% and 85%, respectively. For the month of July, however, when the Delta variant was the predominant strain, Moderna effectiveness against infection dropped to 76% and Pfizer’s dropped to 42%. Moderna was also 2 times more effective than Pfizer in preventing “breakthrough” infections in vaccinated subjects. Focusing solely on Florida with a high infection rate of Delta Covid variants, among the fully vaccinated, the risk of Covid infection was 60% less among Moderna recipients than Pfizer. Other studies have also shown slightly less effective protection from the vaccines against Delta than previous Covid strains.

Possible interpretations from these data are that the Moderna vaccine seems more effective against the Delta variant than Pfizer; both vaccines offer protection against Delta infection and, probably, substantially more protection against hospitalization; and, overall, both vaccines offer strong protection against Covid infection generally. These results need to be confirmed by other researchers in other study populations, but the Mayo study results indicate that additional vaccine shots will probably be necessary for those vaccinated with Pfizer and possibly even for those with Moderna. That’s ok, we can live with that. The real intervention we need to implement is to substantially increase the immunized proportion of the US population and the world’s population. Until we achieve that goal, we will always be at risk from the next new variant whatever it may be.

So, what’s the meaning of all of this? The vaccinated are still protected against all current strains of Covid. Moderna seems more effective than Pfizer against the Delta variant. Children’s immune systems may offer much higher effectiveness against Delta with the Pfizer vaccine than was seen in adults in the Mayo Clinic study. Most importantly, “breakthrough” infections in vaccinated subjects are still very rare, with less than 2 Covid infections per thousand vaccinated people. Finally, we’re in good shape, but expect booster shots to be recommended sometime in the near future. Don’t laminate that vaccine card!

Stay safe. Stay informed. Get the shot.