As this new year is prone to pass entirely under the sign of COVID, it might be suitable to have as a first post one related to the submicroscopic virus that changed (and will continue to change) the way we do many things.

 

There appear to be some deep misunderstandings regarding the vaccination campaign that just started in a few countries in the world. I think it is vital to discuss them as understanding the situation better will help us all make better informed decisions. Note that the situation is fluid and unfolding in front of our very eyes, so everything I will discuss below is based on current information as of 1 January 2021.

 

I have discussed in a previous post (about a month ago) which the main vaccine producers are, and how vaccines will get distributed. Thus, this post will focus on the strategic effect of the vaccines program, rather than on any specifics about the players.

 

What the Tests Show

 

By now most of you would have heard that the Pfizer/BioNTech and Moderna vaccine boast approximately 90%-95% efficacy, while the other publicly rolled out vaccine - AstraZeneca/Oxford (AZ), published a much less reassuring figure - approximately 70% efficacy, with a significant disparity in different test groups. Unfortunately, there are many problems and unknowns with this data, and the only thing that could be said with a relative amount of certainty is that the vaccines are safe to use - as safe as most other vaccines everyone has received throughout their life. This by itself is of course very significant, because it means people shouldn't be worried to get the vaccine. However, problems with the tests and test results include:

 

1. Difference in methodology

 

The AZ vaccine reported on efficacy in asymptomatic cases, which is generally expected to be lower, whereas the same was not done for the other two vaccines. Additionally, AZ had two separate test groups - the first one was given a lower dose (LD) vaccine, and then a standard dose (SD) one, whereas the second group was given two standard doses.

 

2. Small sample sizes

 

Note that while the total sample sizes were big enough to be statistically significant (11,636 AZ, 30,420 Moderna, 43,448 Pfizer), the actual numbers of COVID positive test participants were far smaller (per group):

 

AZ SD+SD: 71 placebo, 27 vaccine (62.1% efficacy)

AZ LD+SD: 30 placebo, 3 vaccine (90% efficacy)

Moderna: 185 placebo, 11 vaccine (94.1% efficacy)

Pfizer: 162 placebo, 8 vaccine (95% efficacy)

 

This very small sample size is likely the reason why the AZ tests produced a very odd and as of now unexplained result - the efficacy of the LD+SD combination was significantly higher than the efficacy of the SD+SD combination. This is one of the reasons why AZ are planning on testing a "mixture" of sorts between their vaccine and the Russian Gamaleya vaccine.

 

3. Potentially insufficient data on certain segments

 

For instance, the participants in the AZ tests were 87.9% below the age of 55, while 75.2% of the participants in the Moderna tests were below the age of 65. Additionally, 82.7% of AZ participants, 82.9% of Pfizer participants, and 79.2% of Moderna participants, were whites.

 

This all means that as far as efficacy of the vaccines is concerned, we should take the currently available data with a grain of salt. The actual efficacy in the general population may be higher or lower than the reports suggest. There is of course no data on the duration of immunity achieved. This depends on extraneous factors that are harder to predict, such as the rate and diversity of "stable" mutations of the virus.

 

What We Need to Achieve

 

Some of you may have heard that the main goal of the vaccination campaign is to achieve herd immunity. This can be done by getting a sufficiently large percentage of the population innoculated. However, this is one of the major moving targets. According to different reports, it may require that at least 60% to 70% of the population achieves immunity. This number may rise if (or rather when) the virus becomes more contagious - something that is already happening according to reports coming from the UK and in South Africa where independent mutations, believed to be spreading faster, have been sequenced recently. This means that the effective rate of immunity may need to increase to 80% of the population. If we assume an average efficacy rate across all of the vaccines at 90%, this may mean that as many as 88% of the people may need to be vaccinated before we could achieve herd immunity.

 

And here comes the bad news - this is most likely unachievable in the near term (within 2021), even for the most vaccine-overstocked countries. A number of groups within the general population are not eligible for vaccination - among them children, pregnant women, and people with severe allergies. These groups of people can become eligible only after further tests are conducted, which will take time. They represent well over 12% of the population of any country. Thus, the main goal is not (or rather - cannot be) achieving herd immunity. The main goal is to prevent the heathcare system from getting overburdened.

 

How and When We Can Achieve It

 

There is no data on whether vaccinated individuals can get the virus and can spread it. Thus, the near term goal is to alleviate the huge burden on the healthcare systems around the world by having the most vulnerable groups vaccinated first - medical practitioners, the elderly, and people meeting with many others as a result of their occupation (teachers, police, parts of the public administration). This alone will take several months, even in the countries spearheading the campaign. Only when this is achieved we would be able to think about a period where lockdowns of varying severity may not be part of our everyday life.

 

Experts with the World Health Organization said just a few days ago that based on current evidence, the destiny of COVID may be for it to remain with us for the long term by become endemic like a number of other viruses. In other words, the most likely scenario is that we will not stop the virus, likely ever, but it will eventually mutate into a strain that is less virulent (i.e. produces less severe negative body response). The vaccination campaign may hopefully speed up this process.

 

2021 Timeline of Events

 

The 2021 timeline of events may look like this:

 

January-March 2021

- USA, UK, Canada, EU countries vaccinate their most vulnerable population segments, achieving 10-15% coverage.

- Strict lockdowns for the better part of the period around the world as more aggressive virus strains replace earlier strains.

 

April-September 2021

- USA, UK, Canada, EU countries start a roll-out among the general population, achieving approximately 50% vaccination coverage.

- Developing countries roll out vaccination campaigns, getting approximately 10-30% of their populations innoculated. Large disparities in vaccination rates across different countries.

- Depending on virus mutations, additional lockdowns across the world, although a slight easing may be observed due to the summer season.

 

October-December 2021

- USA, UK, Canada, EU countries, and a few other places, get to a point where they may not need to impose lockdown-level restrictions anymore. Extensive protection measures (mask wearing, disinfection, social distancing) still in place everywhere.

- Some developing countries reach approximately 50% coverage (hopefully Malaysia is one of them). Limited lockdowns may still be needed situationally.

- Third-world countries begin vaccinations.

 

Key challenges and risks include (in no specific order):

 

- Faster mutation rate of the virus toward a strain that is more transmissible, but not necessarily less virulent;

- Pushbacks in developed countries due to fear from vaccine side effects;

- Virus strain to which the current vaccine versions do not provide effective immunity;

- Production and roll-out challenges and bottlenecks (for instance, shortages of pharmaceutical glass, personal protective equipment, suitable storage space);

- Significant disparity between roll-outs in different regions (even more significant than the current projections are);

- General test setbacks with vaccines and vaccine candidates.

 

In other words, the timeline outlined above may be the best case scenario based on currently available data and projections. I will attempt to cover each of the specific challenges in more detail over the course of the next few months.

 

Let's hope for the best!

 

Sources

Safety and Efficacy of the BNT162b2 mRNA Covid-19 Vaccine

Efficacy and Safety of the mRNA-1273 SARS-CoV-2 Vaccine

Oxford–AstraZeneca COVID-19 vaccine efficacy

WHO warns Covid-19 pandemic is 'not necessarily the big one'

UK reports new variant, termed VUI 202012/01

South Africa announces a new coronavirus variant