The Joint Committee on Vaccination and Immunisation’s decision to delay the second dose of the Pfizer/BioNTech vaccine in the UK until 12 weeks after the first dose—instead of following the recommendation from the manufacturer for a dosing interval of 21 days, or six weeks from the World Health Organization (WHO)—has come under increasing scrutiny. [3-5] 

We believe that frontline health and social care workers, and care home workers, need to be given their second dose of the vaccine within the recommended time interval. 

The decision to extend the interval to 12 weeks for the Pfizer/BioNTech second dose is based on the assumption that it is better to have 100% of the vulnerable or at-risk population protected at 60-70% effectiveness, rather than only 50% of the vulnerable or at risk population protected at 95% effectiveness. In order to achieve this, the second dose of the vaccine was delayed, to allow more people to receive their first dose. 

Now that the top four priority groups have received their first dose of the covid-19 vaccine, the vaccination rollout is being opened up to further groups. This is therefore the moment to consider whether some people, such as frontline health and social care workers, should receive their second dose sooner. Providing a first vaccine dose now to people aged 60-69 years without underlying health conditions (priority groups 5 and 7) would reduce hospital admissions from this group in three to six weeks by 60 to 85%, i.e. the net effect would be a reduction in the ratio of hospital admissions over the number of frontline staff, and so reducing the pressure on the NHS. [6] Before there will be noticeable reductions in hospital admissions due to vaccinating these low-risk groups, the denominator of this ratio, i.e. the number of available frontline staff working in high-risk environments of ICU and A&E, is likely to decrease now with every week the 2nd dose is delayed. A large retrospective Israeli cohort study confirmed the trial results of only 51% efficacy 13-24 days after first Pfizer/BioNTech dose, including symptomatic and asymptomatic infections. [7,1]

Another recent retrospective study of Israeli health and social care workers reported substantial early reductions in symptomatic covid-19 rates following the first Pfizer/BioNTech dose administration, with an adjusted rate reduction of 85% during days 15-28 after the first dose.[8] However, this study only reports on symptomatic and exposed health and social care workers, while asymptomatic transmission of SARS-CoV-2 is the Achilles’ heel of covid-19 pandemic control. [9] In our longterm care facility for people with epilepsy and additional co-morbidities, we have consistently observed asymptomatic rates of 60-80% amongst carers and residents. [10] Only a strategy of full vaccination with enhanced surveillance of health and social care workers and residents is likely to reduce asymptomatic transmission, and so prevent, or at least mitigate, outbreaks in long-term care facilities, which often have fatal outcomes.     

In addition to these human resource considerations, frontline health and social care workers are exhausted and feeling let down again. During the first wave, it was due to a lack of personal protective equipment (PPE), now it is the delay of the second covid-19 vaccine dose. It would increase the resilience and morale of frontline health and social care workers to know that they have maximum protection in view of their exposure to a high viral load of covid-19. 

We strongly support the need to give the highest possible protection to health and social care workers and care home workers by giving them their second dose as soon as possible within the manufacturers or the WHO’s recommended time frame. 

Matthias Koepp and Simona Balestrini are consultant neurologists at the National Hospital for Neurology, Queen Square, London. Both have been regularly testing HSCWs and residents in carehomes, vaccinating in the local community and volunteering in intensive care units.

Ronit Pressler is a paediatric neurophysiologist at Great Ormond Street Hospital evaluating encephalopathies in children with paediatric inflammatory multi-system syndrome.

Ozren Tošić is a public health physician advising governments and health care organisations on policies, governance and management

Competing Interests: We have read and understood the BMJ Group policy on declaration of interests and have no competing interests to declare. The views expressed are not the views of the employing organisations or hospitals.

References:

1. Polak FP, Thomas SJ, Kitchin N et al Safety and Efficacy of the BNT162b2 mRNA Covid-19 Vaccine NEJM 2020 DOI: 10.1056/NEJMoa2034577
2. WHO. Interim recommendations for use of the Pfizer BioNTech covid-19 vaccine, BNT162b2, under emergency use listing. 8 January 2021. https://apps.who.int/iris/rest/bitstreams/1326072/retrieve
3. Iacobucci G, Mahase E. Covid-19 vaccination: What’s the evidence for extending the dosing interval? BMJ 2021; 372 :n18
4. Robertson JFR, Sewell HF, Stewart M, Kendrick, Agius RM Covid-19 vaccines: to delay or not to delay second doses. https://blogs.bmj.com/bmj/2021/01/05/covid-19-vaccines-to-delay-or-not-to-delay-second-doses/ 
5. Sewell, HF, Robertson JFR, Stewart M, Kendrick D, Bird SM. Revisiting the UK’s strategy for delaying the second dose of the Pfizer covid-19 vaccine. https://blogs.bmj.com/bmj/2021/01/20/revisiting-the-uks-strategy-for-delaying-the-second-dose-of-the-pfizer-covid-19-vaccine/
6. Vasileiou E, Simpson CR, Robertson C, et al. Effectiveness of first dose of covid-19 vaccines against hospital admissions in Scotland: national prospective cohort study of 5.4 million people. [Preprint.] 2021. www.ed.ac.uk/files/atoms/files/scotland_firstvaccinedata_preprint.pdf..
7. Chodick G, Tene L, Patalon T, Gazit S, Tov AB, Cohen D, Muhsen K. The effectiveness of the first dose of BNT162b2 vaccine in reducing SARS-CoV-2 infection 13-24 days after immunization: real-world evidencemedRxiv 2021.01.27.21250612; doi: https://doi.org/10.1101/2021.01.27.21250612
8. Amit S, Regev-Yochay G, Afek A, Kreiss Y, Leshem E. Early rate reductions of SARS-CoV-2 infection and COVID-19 in BNT162b2 vaccine recipients Published:February 18, 2021DOI:https://doi.org/10.1016/S0140-6736(21)00448-7
9. Gandhi M, Yokoe DS, Havlir DV. Asymptomatic Transmission, the Achilles’ Heel of Current Strategies to Control Covid-19. N Engl J Med 2020; 382:2158-2160
10. Balestrini S, Koepp MJ, Gandhi S, Rickman HM, Shin GY, Houlihan CF, et al. Clinical outcomes of COVID-19 in long-term care facilities for people with epilepsy. Epilepsy Behav. 2021; 115:107602.