Towards herd immunity: It’s complicated

Vaccination programs are well underway in many countries.  The US is currently averaging about 2 million doses per day and President has indicated that there will be enough doses for all US adults by June (600 million by late July).  In the meantime, …

the huge ~2 trillion dollar stimulus package is almost a reality, and the mortgage relief program has been extended to the end of June 2021.  The road to herd immunity and perhaps a return to some form of “normality” is looking promising at the moment.

The magic range to reach herd immunity is between 70-80% and it important to vaccinate not only the more affluent countries but everyone. In this context, China’s Sinovac and Russia’s Sputnik V vaccines are important; both have pledged millions of vaccine doses including to less affluent countries.  The US President has also indicated a $4 billion global vaccine program.  Given the efficacy of the Pfizer-BioNTech, Moderna, and the recently approved Johnson and Johnson vaccines, together with the urgency to vaccinate as many people as possible, we are on good road.  However, there some obstacles, some of which we will discuss here.

Uncontrollable hiccups, like extreme weather and the super-storms in Texas that delayed millions of vaccine doses, and political plays like issues between cities and states in the US, reported problems in Taiwan, and Italy blocking the export of about a quarter million vaccines to Australia, are problems associated with getting vaccine to people. Some other European countries including Kosovo, Montenegro, Bosnia, Albania, and Northern Macedonia have also reported problems with receiving vaccine shipments.

Apart from issues with vaccine distribution and getting enough doses to countries and people, vaccine hesitancy is concern.  Luckily, the findings from credible surveys indicate that the approximately 25% are against getting vaccinated – if this number holds, it is within the acceptable range for herd immunity.  The talk of vaccination or immunity passports might skew a few of the unwilling people into accepting the vaccine; but it could also go the other way.  Without any expertise in bioethics, my initial thought is that vaccination passports might be a good idea; I wouldn’t mind a momento of my vaccination that I can frame; but maybe I’m naïve!

Regarding immunity – serious questions still remain as to how long immunity from vaccination will last; time frames from a few months to two years are currently being thrown around but it doesn’t feel like we know exactly. A good idea that has been suggested is to pool data on the effectiveness and longevity of immunity following vaccination for the different COVID-19 vaccines.  This will allow for accumulation of powerful and meaningful data; we need to quickly workout the spacing between vaccination schedules; will it be a twice yearly, once every year or every two years, or will the initial vaccination protocols suffice? In another immunity related topic, major players are now working on next generation vaccines that may stimulate T cells (the cells responsible for 1) fighting infection and 2) forming long-term memory to protect from future infection.  Interestingly, the blood type topic has been rekindled with new findings indicated that people with type A blood might be more susceptible to infection and disease severity; a very interesting area of research.

Of course, established and emerging SARS-CoV-2 variants are of some concern with the UK, Brazil and South African variants being the most well investigated.  Early understanding is that the major Pfizer-BioNtech and Moderna vaccines will be effective against these variants but emerging variants will remain an issue; with respect to effectiveness against the South African variant, the AstraZeneca COVID-19 vaccine might be a bit sketchy following reports that South Africa will share millions of doses with other African countries in favour of the Johnson and Johnson vaccine, which is about to be distributed in that country.  Again, the key players are working on modifying vaccines to tackle current and emerging variants, and it is anticipated that they will not require the extensive testing that the originals needed before they can be distributed.

Although not directly related to herd immunity, the issue of long-haulers is gaining attention with ~30% of people with severe COVID-19 disease reporting long-term complications.  Fatigue and brain fog are the major long-term complications reported with recent findings indicating that SARS-CoV-2 can infect the human brain.  Eye problems and loss of taste and smell also appear to be problems that may last for months.  Given the number of people that have been infected, this is a significant issue and a topic that is a priority for investigation by the National Institutes of Health.

Gwenyth Paltrow recently announced that following COVID-19 she still suffers from neurological conditions.  In other celebrity news, it has been reported that the former US President and First Lady were vaccinated in January, and Dolly Parton repped vaccination by singing a tune of her mega-hit but with the word “Vaccine” replacing “Jolene”! Bill Gates’ daughter made jokes after receiving her first COVID-19 dose (debunking conspiracy theories involving her dad), and Mark Zuckerberg played political games with Australia, by blocking and unblocking Facebook news, much of it related to COVID-19 and vaccination programs. Finally, vaccine selfies have become a staple from celebrities and ordinary folk; which could be a good thing!

What is not a good thing is some group of doctors in Melbourne, persisting with hyrodoxychloroquine, despite current reccomendations. Antiviral therapies have been disappointing during this pandemic and we will revisit in a future issue.

Until next time …