Ring vaccination

{{short description|Strategy to inhibit the spread of a disease by vaccinating those most likely to be infected}}

{{Infobox medical intervention

| name = Ring vaccination

| synonym =

| image = US Navy 030124-N-0382M-502 Hospital Corpsman 2nd Class Brian Campbell from Kannapolis, N.C., gives a patient a shot to treat an allergic reaction.jpg

| caption = A vaccination

| alt =

| pronounce =

| specialty =

| synonyms =

| ICD10 =

| ICD9 =

| ICD9unlinked =

| CPT =

| MeshID =

| LOINC =

| other_codes =

| MedlinePlus =

| eMedicine =

}}

Ring vaccination is a strategy to inhibit the spread of a disease by vaccinating those who are most likely to be infected.{{Cite journal |last1=Kucharski |first1=Adam J. |last2=Eggo |first2=Rosalind M. |last3=Watson |first3=Conall H. |last4=Camacho |first4=Anton |last5=Funk |first5=Sebastian |last6=Edmunds |first6=W. John |date=2016 |title=Effectiveness of Ring Vaccination as Control Strategy for Ebola Virus Disease |journal=Emerging Infectious Diseases|volume=22|issue=1|pages=105–108|doi=10.3201/eid2201.151410 |pmc=4696719 |pmid=26691346}}

This strategy vaccinates the contacts of confirmed patients, and people who are in close contact with those contacts. This way, everyone who has been, or could have been, exposed to a patient receives the vaccine, creating a 'ring' of protection that can limit the spread of a pathogen.

Ring vaccination requires thorough and rapid surveillance and epidemiologic case investigation. The Intensified Smallpox Eradication Program used this strategy with great success in its efforts to eradicate smallpox in the latter half of the 20th century.{{Cite web|url=https://www.cdc.gov/smallpox/bioterrorism-response-planning/public-health/ring-vaccination.html|title=Ring Vaccination | Smallpox | CDC|date=November 29, 2019|website=www.cdc.gov}}

Medical use

File:Bundesarchiv Bild 183-92498-0001, Berlin, Ruhrepedemie, Impfung.jpg epidemic, Berlin, 1962]]

When someone falls ill, people they might have infected should be vaccinated. Contacts who might have been infected typically include family, neighbours, and friends. Several layers of contacts may be vaccinated (the contacts, the contacts' contacts, the contact's contacts' contacts, etc.).{{cite web |title=Ring Vaccination: Smallpox {{!}} CDC |url=https://www.cdc.gov/smallpox/bioterrorism-response-planning/public-health/ring-vaccination.html |website=www.cdc.gov |publisher=US Centers for Disease Control |accessdate=19 May 2019 |language=en-us |date=15 February 2019}}

Ring vaccination relies on contact tracing to determine possible infections. However, this can be difficult. In some cases, it is preferable to vaccinate as many people as possible within the geographic area of known infection (geographically-targeted reactive vaccination). If the infections occur within a defined geographic boundary, it may be preferable to vaccinate the entire community in which the illness has appeared, rather than explicitly tracing contacts.

Many vaccines take several weeks to induce immunity, and thus do not provide immediate protection.{{cite web |title=Understanding How Vaccines Work {{!}} CDC |url=https://www.cdc.gov/vaccines/hcp/conversations/understanding-vacc-work.html |website=www.cdc.gov |publisher=US Centers for Disease Control |accessdate=19 May 2019 |language=en-us |date=13 March 2019}} However, even if some of the ill person's contacts are already infected, ring vaccination can prevent the virus from being transmitted again, to the ill contacts' contacts.{{medical citation needed|date=July 2015}} A few vaccines can protect even if they are given just after infection; ring vaccination is somewhat more effective for vaccines providing this post-exposure prophylaxis.{{cite journal |last1=Walldorf |first1=JA |last2=Cloessner |first2=EA |last3=Hyde |first3=TB |last4=MacNeil |first4=A |last5=CDC Emergency Ebola Vaccine |first5=Taskforce. |title=Considerations for use of Ebola vaccine during an emergency response. |journal=Vaccine |volume=37 |issue=48 |pages=7190–7200 |date=7 September 2017 |doi=10.1016/j.vaccine.2017.08.058 |pmid=28890191 |pmc=5842136 }}

Advantages

When responding to a possible outbreak, health officials should consider which is best, ring vaccination or mass vaccination. In some outbreaks, it might be better to only vaccinate those directly exposed; variable factors (such as demographics and the vaccine that is available) can make one method or the other safer, with fewer people experiencing side-effects when the same number are protected from the disease.{{Cite journal|title = Frequency of Adverse Events after Vaccination with Different Vaccinia Strains|journal = PLOS Medicine|date = 2006-08-01|issn = 1549-1277|pmc = 1551910|pmid = 16933957|volume = 3|issue = 8|doi = 10.1371/journal.pmed.0030272|first1 = Mirjam|last1 = Kretzschmar|first2 = Jacco|last2 = Wallinga|first3 = Peter|last3 = Teunis|first4 = Shuqin|last4 = Xing|first5 = Rafael|last5 = Mikolajczyk|pages=e272 | doi-access=free }}

History

Ring vaccination was used in Leicester, England in the late 19th-century.Edward A. Belongia and Allison L. Naleway, [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1069029/ Smallpox Vaccine: The Good, the Bad, and the Ugly], Clin Med Res. 2003 Apr; 1(2): 87–92. {{doi|10.3121/cmr.1.2.87}}

It was also used in the mid-20th century in the eradication of smallpox.{{Cite journal

| pmid = 7044193

| year = 1982

| last1 = Strassburg

| first1 = M. A.

| title = The global eradication of smallpox

| journal = American Journal of Infection Control

| volume = 10

| issue = 2

| pages = 53–9

| doi=10.1016/0196-6553(82)90003-7

}}{{cite press release |title=World on the verge of an effective Ebola vaccine|url=http://who.int/mediacentre/news/releases/2015/effective-ebola-vaccine/en/ |archive-url=https://web.archive.org/web/20150731200521/http://www.who.int/mediacentre/news/releases/2015/effective-ebola-vaccine/en/ |url-status=dead |archive-date=July 31, 2015 |publisher=World Health Organization|accessdate=31 July 2015}}

It was used experimentally in the Ebola virus epidemic in West Africa.{{cite web |url= https://www.bbc.co.uk/news/health-33733711|title= Ebola vaccine is 'potential game-changer'|author=James Gallagher |date= 31 July 2015|publisher= BBC News Health |access-date= 30 July 2015}}{{cite journal |last= Henao-Restrepo|first= Ana Maria|date= 31 July 2015|title= Efficacy and effectiveness of an rVSV-vectored vaccine expressing Ebola surface glycoprotein: interim results from the Guinea ring vaccination cluster-randomised trial|journal= The Lancet|volume= 386|issue= 9996|pages= 857–866|doi= 10.1016/S0140-6736(15)61117-5|display-authors=etal |pmid=26248676|hdl= 10144/575218|s2cid= 40830730|hdl-access= free}}

In 2018, health authorities used a ring vaccination strategy to try to suppress the 2018 Équateur province Ebola outbreak. This involved vaccinating only those most likely to be infected; direct contacts of infected individuals, and contacts of those contacts. The vaccine used was rVSV-ZEBOV.{{Cite news|url=https://www.npr.org/sections/goatsandsoda/2018/05/15/611267872/can-the-new-ebola-vaccine-stop-the-latest-outbreak|title=Can The New Ebola Vaccine Stop The Latest Outbreak?|last=Aizenman|first=Nurith|date=May 15, 2018|work=NPR.org|access-date=2018-05-16|language=en}}

Ring vaccination has been used extensively in the 2018 Kivu Ebola outbreak, with over 90,000 people vaccinated. In April 2019, the WHO published the preliminary results of the research by its research, in association with the DRC's Institut National pour la Recherche Biomedicale, into the effectiveness of the ring vaccination program, stating that the rVSV-ZEBOV-GP vaccine had been 97.5% effective at stopping Ebola transmission, relative to no vaccination.{{Cite web|url=https://arstechnica.com/science/2019/04/ebola-vaccine-is-97-5-effective-early-outbreak-data-suggests/ |title=As Ebola outbreak rages, vaccine is 97.5% effective, protecting over 90K people|last=Mole|first=Beth|date=2019-04-16|website=Ars Technica|language=en-us|access-date=2019-04-17}}{{Cite web|url=https://www.who.int/csr/resources/publications/ebola/ebola-ring-vaccination-results-12-april-2019.pdf |title=Ebola Ring Vaccination Results 12 April 2019|date=12 April 2019 |website=www.who.int|access-date=17 April 2019}}

Ring vaccination

Medical use

Advantages

History

See also

References

Further reading