The following information was received on June 21 from Dr. Rob Cushman, Acting Medical Officer of Health for Renfrew County and District Health Unit (above photo YouTube/RCDHU):
This correspondence follows recent changes introduced by the provincial government in regard to the COVID-19 vaccine rollout. While the COVID-19 vaccine rollout has been progressing at an impressive rate across Renfrew County and District (RCD), we know that the information is everchanging and can be confusing for residents.
Mixing vaccines
First, interchanging or mixing vaccines is a safe and effective option to gain strong protection from COVID-19. Contrary to what many believe, interchanging vaccines is not a new practice and has been done safely and effectively for years in other vaccination series such as influenza, hepatitis A, and others.
Secondly, due to the recent surge in the Delta Variant of Concern across the province, and an increase in Moderna vaccine shipments, the provincial government is encouraging all residents to book their second doses earlier than previously expected. Therefore, I am urging residents to book an early second dose appointment as soon as possible, as locally, we are anticipating cancelling all previously scheduled appointments on or after July 18th.
Lastly, residents should know that while there is an increase in Moderna vaccine shipments, there is an Ontario-wide shipment delay for the Pfizer vaccine. This may mean that residents will not be able get the same vaccine as their first dose. However, we all must remember that to keep our families, friends, and communities safe, the best vaccine for your second dose, is the first one available to you.
Eligibility for early second dose appointments
Early second dose appointments are available for anyone who is 18 years of age or older who has had an mRNA vaccine (Pfizer or Moderna) for at least 28 days, or for those who have had an AstraZeneca vaccine for at least 8 weeks.
Dr. Cushman accompanied this information with a video message which can be viewed below:
Cushman,Dr.R.,RCDHU(2021,June21) Key Messages Regarding COVID-19 Vaccine Rollout [Memorandum to Media]

Most people unfortunately do not understand anything about vaccines. Covid is here to stay so the human race will be in an ongoing “war” with it for generations to come. The purpose of vaccines is to stimulate antibodies which will mitigate the symptoms of a Covid infection and hopefully help your body to completely repel an infection. However Covid mutates incessantly and new variants keep coming along which can overcome old defenses so we will always need regular booster immunizations, just like for influenza. to repel these new variants. Basically it’s ok to mix all approved vaccines in succession although some work better together than others:- however the public-health people like to play it safe and test these combinations first to ensure efficacy and to prevent unexpected adverse outcomes because this is still a very new and rapidly evolving area of public health science. The mRNA vaccines are a very new type of vaccine but they all work in much the same way and they are completely compatible with each other. However the public needs to understand that this essentially a new kind of microbiological “war” without end and there will always need to be regular booster vaccinations and in the meantime we will need to take the usual precautions such as social distancing, washing hands, and other types of personal hygiene the same as we do for influenza and common colds and gastro-intestinal pathogens etc:- welcome to the new Covid world!