A 9-month study on the efficacy of the COVID-19 vaccine in North Carolina

New paper New England Journal of Medicine The report increased the number of breakthrough infections with agents behind severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and pandemic ongoing coronavirus disease 2019 (COVID-19). .. This is despite the widespread deployment of the COVID-19 vaccine in the United States. This paper explores the reasons behind this phenomenon.

study: Efficacy of Covid-19 Vaccine for 9 Months in North Carolina.. Image Credit: Alexander Lukatskiy / Shutterstock

Background

The unprecedented speed when the vaccine was developed to counter the explosive increase in the case of COVID-19, and the overwhelming demands made in medical facilities for the treatment of moderate to critical diseases, It was a modern wonder.The first two vaccines to receive an emergency use authorization were developed on the Messenger Ribonucleic Acid (mRNA) platform, both reporting about 95%. Effectiveness In advanced clinical trials.

Johnson & Johnson’s third vaccine was subsequently approved for emergency use.

Breakthrough infections that began in the summer of 2021 and continued into the fall increased, despite the initial decline in the number of cases. This has been the subject of much research. Still, in most cases, it is not large enough to determine why an increase in infection was observed. Perhaps due to weakened immunity, newly emerging mutants, especially delta mutants, are highly infectious and resistant to antibody-mediated neutralization after vaccination. Natural infection.

The current study uses data collected in North Carolina for vaccine monitoring. This is important because it provides the basis for an actual assessment of vaccine efficacy. The aim was to estimate the vaccine efficacy of all three US vaccines against infection, symptomatic disease, and death during the three months following vaccination.

North Carolina has a diverse population, with more blacks, Asians, and Pacific Islanders than the national average. The most commonly used vaccine was Pfizer, followed by the Moderna vaccine.

What did the study show?

The two-dose vaccine regimen of either mRNA vaccine showed peak efficacy at about 95% 2 months after the first dose, but then began to decline. For the Pfizer vaccine, the lowest score at this point was 80% for modern times vs. less than about 67% in 7 months. Thus, the efficacy of the two vaccines showed a difference of 10 percentage points to 7 percentage points between 4 and 7 months at 10 months.

With the J & J vaccine (single inoculation regimen), efficacy peaked at 75% in 1 month, began to decline almost immediately, and reached 59% in 5 months. The vaccine was first introduced much later than the other two, so at the time of the study only 5 months of follow-up was available.

However, the efficacy of those initially vaccinated with the Moderna or Pfizer mRNA vaccine prior to March 2021 was reduced by 10 and 15 percent points compared to previous fall, due to Delta’s antigenic characteristics. Shows additional contributions. Subspecies exacerbate the decline in vaccine-induced protection.

Hospitalization data were incomplete, but available data showed that Pfizer’s defense against serious illnesses requiring hospitalization was 96% in two months, compared to 97% in Moderna. It was stable at 88% and 94%, respectively, for 7 months. With the J & J vaccine, the peak effect was 86% in 2 months, but decreased to 80% by 6 months.

The lowest efficacy against infection or hospitalization was among the elderly (65 years and older) compared to young adults. Nevertheless, general trends were similar for most parameters, such as gender, race, geographic location, and county-wide immunization rates. Vaccination over different time ranges, suggesting that weakened immunity is the main reason for economic improvement in infectious diseases, if different rates of decline are not followed depending on the phase of the pandemic, even if it occurs between groups. doing.

In the case of death from COVID-19, the Pfizer and Moderna vaccines provided 98% and 99% protection in 2 months and remained at 91% and 96% in up to 7 months, respectively. This was 86% and> 70 for the J & J vaccine, respectively, but less reliable.

Therefore, all three vaccines were optimal for the prevention of serious and deadly diseases caused by SARS-CoV-2 infection, but they also played an excellent role in the prevention of long-term infection. The mRNA vaccine was consistently more defensive than the J & J vaccine.

What is the impact?

The results of this study show the actual vaccine efficacy in populations of symptomatic and asymptomatic infections, covering all grades of severity. All three COVID-19 vaccines were very effective in reducing the risk of hospitalization and death. The mRNA vaccine was more effective, especially for serious illnesses, deaths and infectious diseases.

The decline in defense against infection over time was due to weakened immunity and the emergence of delta variants. In Israel, for example, breakthrough infection rates were 60% higher in those who received double vaccination in January compared to those who received both doses in March 2021, whereas severe illness It was 80% higher in the former group.

Follow-up studies have been presented that combine data from multiple states to validate estimates of the efficacy of these vaccines over 9 months and the efficacy of additional booster doses. This also helps determine the need for such a program.