As the United States grapples with another deadly wave of Covid-19 pandemic, while vaccinations levels were already 40%+ (fully vaccinated) for the population as far back as in May itself, there is a sense of unease and question marks on vaccine effectiveness.
Looking closely at the data, USA numbers on face value raises some obvious questions.. with vaccination levels now touching ~55% mark(~65% for people with at least 1 dose), the number of cases and deaths defy basic logic. The peak of recent wave was ~70% as high as the last one seen in early this year, even mortality numbers show a grim picture with recent peak being ~60% of previous peak.
So, are the vaccines really 10X – 20X effective as being claimed in several earlier studies?
Luckily in recent weeks, lot of new data has been published to answer this question more effectively.
To understand why this recent wave is so devastating despite high vaccination levels in population, we need to first acknowledge the presence of more contagious and deadlier variants of the virus.
The Delta variant that contributed ~30% of all cases till mid-Jun now contributes almost all cases.
This new composition of virus variants dramatically affects our susceptibility to new infections and related complications. Hence comparison with previous peaks are to be taken in that light
CDC( Center for Disease Control and Prevention) has come up with a new study in September that further clarifies on significant(though reduced) effectiveness of Covid-19 vaccines vs new infections, hospitalizations and deaths.
Below is a summary of published data:
This data overwhelmingly supports the case for vaccines and even with reduced effectiveness, vaccines reduces the risks by 10+ times when it comes to hospitalization or deaths.
Only caveat is that the study compares the data of Jun20th-Jul17th vs previous base.. while this recent data captures impact of newer variants, but as the cases in USA actually peaked in Aug/early Sept (hopefully), and the fact that Delta variant prevalence in Jun was still lower, maybe the real extent of the dip in vaccine effectiveness is not captured. We need to wait a bit longer to see a similar study with Aug-Sept data.
Or alternatively, we can already see data from other countries and look for patterns.
One interesting case is UK, where with marginally higher vaccination levels(65% fully vaccinated vs 56% in USA) the country was able to cut the mortality by 90%.
What explains this? Different Vaccines? Different mix of variants? Perhaps Yes for both.
But more importantly, above marginal difference in vaccination levels actually mean that there are ~30% less unvaccinated person for the virus to spread in the population.
So I guess pushing fully vaccinated levels beyond ~65% levels is the first step.
If you haven’t taken the jab, please do so.. with the overwhelming evidence pouring from across the world about Vaccine Effectiveness and Safety.