COVID-19 vaccines: making sense of the guidance

Helen Donovan and Helen Bedford 6 Jan 2021

Changes to the COVID-19 vaccine roll out have understandably caused some concern and confusion and in this blog, we aim to explain the rationale for these changes. 

Illustration of vaccine syringe

There are in fact three vaccines approved for use in the UK against the SARs-CoV2 virus to combat the resulting COVID-19 disease. The vaccine from Moderna has now been approved but supplies wont be available until the spring in the UK. As we talked about in our previous blogs, the Medicines and Healthcare Regulatory Agency (MHRA) approve vaccines for the UK; the Pfizer BioNTech vaccine and the Oxford/AstraZeneca Vaccine Group’s vaccine on 2nd and 30th December respectively and the Moderna vaccine on January 8th. Our focus for now is to roll out the two vaccines we have available, as quickly as we can.

Given the recent emergence of the more highly transmissible variant strain of the SARs-CoV2 and with increasing numbers of people becoming infected and needing hospitalisation, the availability of two vaccines is fantastic news.  

Whilst both vaccines achieve the same aim, the Oxford/AstraZeneca vaccine has particular logistical and operational advantages over the Pfizer BioNTech vaccine. The storage requirements are similar to other routine vaccines and it is easier to prepare for administration. This will ease roll out to large numbers of people over a relatively short period of time. 

The authorisation for use of the Oxford/AstraZeneca vaccine has therefore caused some changes to the previous guidance for roll out of the programme as a whole. These changes have understandably caused some concern and confusion and in this blog, we aim to explain the rationale for these changes, and their safety. 

Rationale for changes to schedule

Both vaccines have been tested in trials and the temporary licence authorisation is based on individuals receiving two doses, to give maximum protection. However, the evidence for both vaccines from data in various phases in the trials show that one dose will give good short-term protection.

Based on the trial data of these two new vaccines, the Green Book, as the recognised UK immunisation and vaccination policy document, chapter for the COVID-19 vaccines (Chapter 14a) advises that the interval between the two doses of vaccine should be a minimum of 21 days for the Pfizer BioNTech vaccine and 28 days for the Oxford/AstraZeneca vaccine. 

As with all vaccines these are minimum gaps. This advice has been amended following the Joint Committee for vaccination and immunisation’s (JCVI) recommendation that the second dose of both vaccines should routinely be scheduled between four and 12 weeks after the first dose. This is for operational purposes, primarily in response to the current high rates of COVID-19 infection causing a public health emergency, and to make sure we can vaccinate as many people with at least one dose of vaccine as soon as possible. 

The evidence shows that the first dose of both Pfizer BioNTech and Oxford/AstraZeneca vaccines are highly effective and that at least initially, protecting more people with a single dose will prevent more deaths and hospitalisations than vaccinating fewer people with two doses. 

Although this new recommendation differs from the previous information provided by the vaccine manufacturers, this approach is justified from the underlying principles of how vaccines work  and that a longer gap would effectively boost longer term protection. 

Giving vaccines outside the manufacturer guidance

Many colleagues are understandably concerned about giving vaccines outside of manufacturers’ guidance and where this places them professionally. Where there are differences between the manufacturer guidance and national policy, the basic vaccination principle is that the Green Book guidance takes precedence (see chapter 4 in the Green Book). The option for a longer gap is clearly explained in the Green Book, and the national protocol and Patient Group Direction (PGD) have been updated to reflect this change.

The revised schedule, rationale and information on the effectiveness of the revised schedule needs to be clearly explained to people. However, if following individual clinical assessment, clinicians feel that a person should be vaccinated as per the original manufacturer dosage schedule recommendation, both the RCN and NMC would support these local decisions. 

Manufacturers’ recommendations regarding vaccines, or indeed any drug, are based on trial data.  In the UK over many decades, the JCVI has advised on vaccine policy for the UK population as an independent expert body. This includes how vaccines are: best managed from an operational perspective and fit with the rest of the vaccine programme; how and where the vaccines should be given; and how best to schedule doses. This informs vaccine policy which is published in the Green Book. 

Recommendations for vaccine doses and schedules which differ to manufacturer guidance are not uncommon. For example, the doses and spacing for HPV, meningococcal and MMR vaccines differ from those in manufacturers’ guidance. The rationale for these changes are based on the first principles of vaccination to maximise the protection of the vaccines for the population. All immunisation procedures are based on currently available evidence and experience of best practice. 

Operational concerns

The speed of change for the dosing schedule has left many concerned about the impact on public trust and confidence.  Original advice of the need for a second dose in three weeks, and then to be told this will need to be longer, could be confusing and cause reduced uptake of either dose.  

Changes to a planned treatment schedule does not invalidate the earlier consent for vaccination providing the individual understands the reasons for the change. Consent for administration of any vaccine is required before each dose and people need to be advised what vaccine they are going to get, the reasons for receiving it and have any concerns addressed.

Second doses are still needed but the longer interval may present additional challenges to ensure people don’t forget. This will need robust call and reminder systems in place.

Managing changes of a new and evolving vaccine programme

Given the scale of the public health emergency, vaccines need to be rolled out at speed as soon as they become available and it is inevitable that guidance will be modified as the situation changes, just as the advice regarding which areas fall into different tiers has changed rapidly.  This presents a challenge to nursing staff vaccinating, dispelling vaccination myths and supporting people who may be hesitating to have the vaccine.

During the early few weeks of using the Pfizer BioNTech COVID-19 mRNA Vaccine BNT162b2 it is clear that each vial, after dilution, will in fact contain 6 doses rather than the stated 5. The MHRA and JCVI have now advised that where possible, a sixth dose can be used from each vial and this is now stated in the Green Book. 

These rapid changes to advice over the past few weeks underline the necessity for all clinicians involved in the programme to keep up to date with the published guidance in the green book and policy as informed by JCVI. Our COVID-19 vaccination pages are also updated as soon as new information becomes available to support all those involved in this vital vaccination programme.

Helen Donovan

Helen Donovan and Helen Bedford

Helen Donovan, RCN Professional Lead for Public health

Helen Bedford, Professor of Children’s Health, UCL Great Ormond Street Institute of Child Health

Page last updated - 03/07/2021