Covid-19 Pandemic: Part 8: Pandemic Ending: How Did We Reach Here?

Published in May 2022

In this paper we discussed the changing scenario and how the pandemic is gradually changing to an endemic phase and what factors contributed to the declining trend of the disease. While the success goes to vaccination coverage and understanding the disease transmission and treatment, the threat of the endemic disease remains. We also discussed unacceptable vaccine distribution disparity at the global level and what best can be done to reduce the uneven distribution and utilization of the vaccine.

We discussed the historical context of Covid-19 pandemic, followed by the signs, symptoms and how it affects our body, various diagnostic tests, and the virus and its variants, general measures of protection and types of vaccines and their doses and vaccine hesitancy and limitations. In this month’s edition we discuss the changing scenario for good and the reasons of the success behind this and way forward. We also study the disparity in vaccine coverage and potential dangers associated with that.

Epidemic to Endemic Phase: Globally overall case rates are on decline though at places the new variant of Covid-19 continues to increase the cases. In USA 7 day moving average increased to 42605 from previous 7-day average of 31495. This is attributed to Omicron sub-variant.

Community Level for Covid-19: In the month of February 2022, CDC proposed a new indicator called Community Level based on three parameters:

Number of new cases per 100,000 population
Number of new cases hospitalized per 100,000 population
Percentage of beds occupied by Covid-19 patients in the hospital.

Based on this criteria community is divided in to low, medium, and high level. CDC further provides guidelines for what measures need to be observed based on this level of community level. (See fig 1)

Based on these criteria, Currently, there are 39 (1.21%) counties, districts, or territories with a high COVID-19 Community Level, 231 (7.17%) counties with a medium Community Level, and 2,954 (91.63%) counties with a low Community Level. This represents a slight (0.78%) increase in the number of high-level counties, a small (+1.67%) increase in the number of medium-level counties, and a corresponding (−2.45%) decrease in the number of low-level counties suggesting slight increase in the level of Covid-19 in the last one week. However Over 91% are in low community level of Covid-19 and that includes Maricopa County. Thus, we have a slight relief at present. Recommendation for Maricopa County residents at present is to remain up to date with vaccine, which means all the recommended vaccine should be completed including eligible boosters. If there are symptoms related to Covid-19 then get tested. CDC however encourages to wear the mask any time and surely while traveling in public transportations.

How Did We Have Low Community Level Now?

After massive spread of pandemic, how did we have low level of community level now? Based on the low level of Covid-19 on March 31^st, 2022, Governor Doug Ducey lifted the covid emergency that was placed in March 2020 for the state of Arizona.

The reduction is achieved with improved level of herd immunity. So, let us understand what is herd immunity?

Herd Immunity

Herd immunity is the indirect protection from an infectious disease that happens when a population is immune either through vaccination or immunity developed through previous infection. So, if a large proportion of community is immune, either by vaccine or by infection and then survival, those who are not vaccinated yet are also partially protected because the infection cannot reach them. This will slow down the epidemic and community will be saved.

Herd Immunity is increased by two ways: 1. By Vaccination of large proportion of people 2. By People getting natural infection and then getting cured.

State of Arizona has by now 2 million cases of Covid recorded in the population of 7.4 million giving a rate of 27.3% of people got Covid-19. Further 70% of persons are vaccinated with at least one dose of the vaccine and 60% are fully vaccinated. Thus 60% fully vaccinated and 27% with the natural infection, assuming some overlap on them, then also over 70% are having immunity against Covid-19 either naturally by infection or due to vaccine. This is the threshold needed for herd immunity to decrease the Covid-19 cases in the community. That explains the epidemic going down to endemicity.

Endemic means the disease is relatively at lower level and predictable level of occurrence. Covid-19 is here to stay, and it is unlikely to completely disappear. Endemic Covid-19 does not mean we have no more to worry. It just means people can return to their normal life with due precautions. They include most importantly to remain up to date with the vaccine recommendation for their age and get themselves tested if there are any symptoms. Tuberculosis, HIV, Malaria, and many other endemic diseases continue to kill millions of people every year and endemic word is a relative term and does not mean the disease is gone. Endemic phase will turn to epidemic with new variants and different seasons.

Vaccine Coverage Globally and How Does It Matter To Us?

Nearly 65% of Global population is vaccinated with at least one vaccine after two years of vaccine made available. However, the distribution of vaccine is far from satisfactory. Less than 15% of the low-income countries’ population has received their first dose of the vaccine. This is not right morally and ethically. Our vaccine production is a matter of great pride for the remarkable speed with which it was produced and made available but as the global population we have failed to provide everyone who needs it in time. Much more than distribution problem and ethical failure, this is also a dangerous situation epidemiologically. Where the vaccine is not yet available, virus continues to spread uninterrupted and that gives the virus ample opportunities to mutate and come up with new variants. These new variants of the viruses can globally travel and come back to the developed world and start a new epidemic that will not be controlled by present vaccinations. So, if not for moral grounds, if not for humanitarian grounds, for their own self-interest also developed countries need to ensure that vaccine reaches and is used in every country for every human being.

Coming Up

Next month we will discuss what lessons did we learn from Covid-19 Pandemic and how do we modify our life and our future based on the lessons. We will also quantify the economic loss globally and discuss some splendid achievements and some serious losses