5 August 2021 Episode 159 Delta transmissibility, vaccine justice and Africa

Thu, 08/05/2021 - 18:39

Dear colleagues,

For once this episode is not so much on scientific data, but more on reflections and principles.

Ep 159-1:  A colleague provided a very interesting powerpoint from CDC with unpublished data on delta.   The important point is that, while vaccination is very effective to prevent hospitalization and death by delta, vaccinated people can get infected and have a high viral load, hence highly transmissible. 

Summary slide 22:

▪ Delta is different from previous strains

– Highly contagious

– Likely more severe

Breakthrough infections may be as transmissible as unvaccinated cases

▪ Vaccines prevent >90% of severe disease, but may be less effective at preventing

infection or transmission

– Therefore, more breakthrough and more community spread despite vaccination

Non-pharmacological interventions such as masking are essential to prevent continued spread with current vaccine coverage


This new situation requires correct communication to the general public:  slide 23


– Improve public’s understanding of breakthrough infections

– Improve communications around individual risk among vaccinated

• Risk of severe disease or death reduced 10-fold or greater in vaccinated

• Risk of infection reduced 3-fold in vaccinated


– Consider vaccine mandatory vaccination for Health Care Personnel to protect vulnerable populations

– Universal masking for source control and prevention

– Reconsider other community mitigation strategies

Clearly, the challenge is to keep to general public, including youngsters, motivated for vaccination, while “total freedom” cannot be granted….

Ep 159-2: An interesting clarification about the “test negative design” real world studies on vaccines that I presented in previous episodes.   This design is a form of case–control study in which persons testing positive for a disease after seeking health care (or because of a surveillance test) constitute the cases, whereas controls are selected from persons who test negative in the same situation.  As a consequence many biases are excluded e.g. the variants circulating are the same. 


I also read a few contributions on Africa and international solidarity in Nature, Science and NEJM, because they provide different perspectives.    

Ep 159-3:  An emotional call from Liberia by Dr. Mosoka Fallah: “We lack vaccines and we are gasping for air”.  He makes several valid points:

  • During EBOLA, international solidarity only realized when cases emerged in the North
  • Africa may need a “Marshall” plan. whereby prosperous nations freely share vaccines, manufacturing capacity and resources — if not for the sake of their consciences,bthen for health security.
  • Regions where COVID-19 cases are allowed to soar are the places where the next variant will emerge. That could undo all the advances made with the vaccine roll-out in developed countries.


Ep 159-4:  Nevertheless, things are more complicated than just delivering money, ventilators or vaccines, as Dr. Amani Adidja et al comment:

Cameroon, a nation of 25 million, has enough vaccine for 72% of those at high risk

(812,300 people).  By mid-June just 2.3% of them had been fully vaccinated.  Only around

one in five health workers had accepted shots.

Fears about extremely rare adverse events are widespread; fear of the pandemic is not.

Urgent investment is needed to counter misinformation in community-specific ways

Low-income countries must act now to boost confidence in vaccines.


Ep 159-5: A very thorough analysis on vaccine injustice and ways to avoid it, is presented by Suerie Moon et al. Besides all the reasonable principles, the Figure on public and philanthropic investment of 5.6 billion $  is interesting:

  • As expected, the US was the major funding (over 2 billion) and Janssen an Moderna the biggest recipients (each about 1 billion).
  • However, Germany has also invested 1.5 billion, with Pfizer-BioNtech and CureVac as the main recipients
  • Next comes Hong Kong with 500 million for SinoVac (producing the inactivated CoronaVac)
  • Also the UK has invested just under 500 million, with, of course Oxfor-Astra-Zeneca as a main recipient.
  • The Coalition for Epidemic Preparedness Innovations (CEPI) was funded by EU and Canada and UK, and various countries (Germany, Norway etc) but NOT by US. And supported various vaccines, including NovaVax and Sichuan Clover, both developing a S protein vaccine.
  • The “input” from China is relatively modest: only 145 million for Sinopharm (the inactivated BBPI vaccine)  
  • The input from France is almost negligible:  17 million.
  • India is not mentioned?  


Clearly, the portfolio developed by CEPI is very diverse, spreading out the risks, but it nevertheless failed to address the huge North-South “gap” !  


Ep 159-6: Nachega et al take a number of practical lessons from the HIV response and apply it to COVID vaccine roll-out.  See the very clear table.

Obviously, there are also big differences between the HIV and COVID pandemic, in that HIV is much less infectious and doesn’t spread in the air.  So there was in principle more time. 


It took over 10 years of intensive lobbying between the development of highly active antiviral treatment and universal access (and it is still only partly realized).  Nevertheless, important milestones and attainment such as manufacturing in the South of ART are an example for COVID vaccines.


If you are interested in profound discussions on these topics please join the parallel e-mail group  covid19ssa@googlegroups.com.      

Best wishes;