There are 60 candidate vaccines in clinical development: 11 with ongoing Phase 3 trials. Of these, eight (8) vaccine developers have received emergency authorization for use (or equivalent) in various countries to date. Pfizer-BioNTech’s vaccine is the first to be reviewed and approved by the World Health Organization for its Emergency Use Listing, which means it will be the first that would be offered to CARPHA Member States via COVAX and the PAHO Revolving Fund. Based on the projected dates for the completion of reviews for other candidates by the WHO, CARPHA Member States may likely have seven vaccine options by the end of March.

The Caribbean Public Health Agency urges the reliance on existing scientific evidence to support public health policy, particularly as it relates to maintaining public health measures and social restrictions until countries have ensured that a sufficient proportion of the population is immune to SARS-CoV-2 virus. The CARPHA CRS collaborates with the World Health Organization and the Pan American Health Organization in terms of the recognition of regulatory authorities used in its procedure for the verification of COVID-19 products that have been assessed by trusted authorities and recommended for emergency use authorization.

For COVID-19 vaccines that require two doses, the first initiates the immunity-building step but the second is needed to complete the process (boost the system for a response when exposed to the virus). Between the first and second dose, full immunity is not assured, so persons are still at risk of infection. In addition, past data indicate that it requires another 2 weeks after the second dos for full immunity. Persons who have received 1 or 2 doses should still follow the public health precautions of social distancing, hand-hygiene (washing & sanitizing) and wearing of facial masks.

Vaccine developers are not yet sure of how long immunity will last after vaccination against COVID-19, and are still studying this aspect. Once the information is available through monitoring of trial participants, the vaccine information will be updated to indicate if the vaccine will be needed annually, or otherwise. In the meantime, persons who have been vaccinated (complete vaccine schedule) are advised to maintain the social restrictions to reduce the risk of exposure to the virus.

It is recommended that social restrictions may be relaxed when herd immunity is achieved at a national level. For SARS-CoV-2, this has been estimated when approximately 60-70% of the population acquire immunity to break the chain of transmission. Until then, persons who have been vaccinated should continue with the ascribed social restrictions of hand-washing, social distancing, and face masks, as others may not be immune.

At this time, the evidence is not clear on the interchangeability of the vaccines made by different developers, including those made using the same vaccine platform. Some national authorities have introduced interchangeability as a contingency in the event the second dose of the initial brand of vaccine administered is not available when the patient returns, rather than send the patient away without it. CARPHA advises Member States to monitor the scientific evidence as it relates to interchangeability, and be guided accordingly.

CARPHA’s Caribbean Regulatory System (CRS) will apply its reliance procedure to verify vaccines with emergency use authorization granted by stringent regulatory authorities of reference. To support regional surveillance of vaccine safety, the CRS will support reporting of adverse events following immunization (AEFIs) and reporting of substandard / falsified / unregistered COVID-19 vaccines found in Member States. One planned action involves preparation and maintenance of a public list of COVID-19 vaccines authorized by CARPHA Member States for market registration and/or importation. This list is intended to help health professionals and law enforcement agencies to check the registration status of the vaccine in the country, in an effort to fight the entry of falsified vaccines.

Vaccine development is ongoing in different countries of the Americas, including Brazil and Cuba. Vaccines that are developed and/or approved for use in these countries may be considered by the national authorities of CARPHA/ CARICOM Member States with the capacity to undertake comprehensive assessments of the quality, efficacy and safety of the vaccines. At this time, the CARPHA CRS does not rely on assessments by Brazil or Cuba for emergency use review procedure for COVID-19 vaccines. The CRS uses regulatory reliance on assessments by national regulatory authorities to make recommendations to Member States. The selection of the national authorities are based on those recognized for the assessment of biologics (biosimilars, vaccines) by the World Health Organization. At this time, the only regulatory authorities from the Americas that are relied on by the CRS for vaccines are: Health Canada, and the US Food and Drug Administration.

National regulatory authorities vary in their regulatory capacity. The given country may have a system for the direct and comprehensive assessment of vaccines prior to market entry. For countries with the capacity to assess vaccines directly, this approach is feasible. However, for countries that do not have the in-house capacity to assess vaccines directly, regulatory reliance on trusted regulatory authorities is recommended. The selection of a trusted authority by CARICOM Member States should be guided by the PAHO / WHO’s assessment of national regulatory authorities for the relevant product type, as regulators that are recognized for assessment of medicines may vary from those that are recognized for the assessment of vaccines or test kits.