Covid Update: Very Scary Variants

There is a widespread belief that the current Omicron COVID virus variants (B1.4 and B1.5) are not as dangerous as the Alpha and Delta strains that were the predominant cause of infections until earlier this summer. Hospitalization and death rates are down from last winter, and many infections in those less than 70 years old result in mild, cold-like symptoms.

It is easy to interpret these data as good news, and perhaps they are, but it is important to remember that the virus has changed but so has the host (us). The majority of us in San Diego county are vaccinated, many have received additional booster shots, and a large (and unknown) number have been infected and recovered. Compared to unvaccinated and uninfected individuals, most of us are somewhat less susceptible to infection and have reduced risk of serious infection. However, it is difficult to make sense of infection rates when so many of us do not report the results of positive home tests. The availability of antiviral medications like Paxlovid should reduce the number of infections that result in hospitalization, so the hospitalization rate is also difficult to compare to previous outbreaks. Infectious disease doctors are much better at treating serious COVID infections than earlier in the pandemic, so even death rates have different meaning now.

There are other confounding effects on local and national death rates. Deaths remain much more common in older individuals with underlying conditions (the median age of death of COVID patients in San Diego in July was 79) and are rare in younger individuals. Although vaccination reduces the risk of death by 2-3-fold, vaccination plus two booster shots is less protective. This may seem counterintuitive until you take into account that older individuals were more likely to get the boosters, and got them earlier than the general population, so they are more likely to have lower immune responses if 4-6 months have elapsed since the last booster shot.

So are the latest COVID Omicron variants less dangerous? The current best answer is probably yes if you are young and healthy, and no if you are older regardless of your vaccination status.

There are new formulations of the Pfizer and Moderna mRNA vaccines in late stages of testing that target the new Omicron variants, and the hope is that they will be available this fall.

Some of us older Del Mar residents can’t wait for their arrival.