Thursday, September 21

The US has good news on COVID vaccine boosters: they protect against omicron and delta

Booster doses of COVID-19 vaccines increased protection against the delta and omicron variants in three studies that looked at infections, hospital admissions and deaths in thousands of patients in the United States.

Third doses of messenger RNA vaccines made by Moderna and the Pfizer-BioNTech partnership were at least 90 percent effective in preventing hospitalizations during the delta and omicron periods, based on an analysis of hundreds of thousands of hospitalizations.

The protection of injections against COVID deaths did decrease after the appearance of omicron, but it was still significant, according to a separate study by the US Centers for Disease Control and Prevention (CDC).

The urgency for vaccinations and boosters has subsided amid reports that omicron causes milder disease than previous variants. However, many hospitals remain overwhelmed by the sheer number of patients infected with the variant, making prevention a key part of the battle against coronavirus.

Booster doses have been controversial, as many low- and middle-income countries have been unable to ensure not even the first vaccines for their populations. Covax, the World Health Organization-backed program to distribute doses equitably around the world, recently reached the milestone of delivering 1 billion doses, while more than 500 million were administered in the US alone.

The WHO has not endorsed the use of boosters, except for vulnerable populations such as the sick and the elderly.

About 63 percent of the US population is fully vaccinated and only 24 percent have received a booster dose, according to the Bloomberg Vaccine Tracker. That compares with 49 percent in Germany and 55 percent in the UK.

The hospitalization study, published in the CDC Morbidity and Mortality Weekly Report, looked at more than 300,000 visits for COVID-19-like illnesses to emergency departments, urgent care clinics, and hospitalizations in 10 states between August and January. The boosters reduced the risk of hospitalization by 94 percent in the delta era and by 90 percent after omicron onset.

In the other study published by the CDC, unvaccinated people they had a 53-fold increased risk of COVID death during October and November compared to those who were vaccinated and boosted. The increased risk to the unvaccinated was reduced to 13-fold during the boom in omicron, which has shown the ability to evade the protection offered by vaccines.

The boosters were supported by a third study that found that the booster doses provide significant protection against symptomatic COVID caused by both delta and omicron. People who received a third dose were less likely to seek care for symptomatic infections than those who received only two or none, according to the study published in the medical journal JAMA.