- Ensure that all displaced people and/or people in shelters (adults
and children), including health workers in the shelters, are vaccinated against measles.
It is necessary to prepare a list of needs to search for and mobilize resources.
- Maintain routine vaccination with the basic vaccination schedule,
since a reduction in coverage in the medium-term could result in a resurgence of
vaccine-preventable diseases that have already been controlled and/or eradicated, such as
measles, polio, whooping cough, diphtheria, and neonatal tetanus.
- Evaluate damage to the cold chain and the loss of biologicals,
syringes and supplies.
- Immediately re-stock vaccines utilized routinely by the national
immunization programs.
- Implement the temporary use of cold boxes (RCW42) to ensure the
conservation of vaccines in the affected areas and their distribution, provided that there
is ice available.
- Implement the use of photovoltaic refrigerators for vaccine storage
and ice production, guaranteeing sufficient batteries.
- Initiate recovery of the cold chain (purchase of refrigerators,
thermos, thermometers, etc.)
Overcrowding and poor water and sanitation favor an
increase in the incidence of diarrheal diseases (associated with sanitation and water
quality) and respiratory diseases (overcrowding). Mass immunization during situations of
natural disasters is counterproductive and diverts limited human resources and materials
from other more effective and urgent measures. Immunization campaigns can give a false
sense of security, leading to the neglect of basic measures of hygiene and sanitation,
which are more important during the emergency.
Mass vaccination would be justified only when the
recommended sanitary measures do not have an effect and if there is evidence of the
progressive increase in the number of cases with the risk of an epidemic. A vaccine with
the following characteristics could be considered useful in this situation:
- A vaccine of proven efficacy, high safety and low reactogenicity
- A vaccine that is easy to apply (single-dose)
- A vaccine that confers rapid and long-lasting protection for people
of all ages.
- Sufficient quantities of vaccine should be available to guarantee the
supply for the entire population at risk.
- Low-cost vaccines.
Regarding questions on the possible use and demand
during an emergency for vaccines that are not included in national immunization programs,
it is important to recognize the costs and mobilization efforts needed to carry out a mass
immunization. The vaccines frequently proposed are those against cholera, typhoid fever,
and meningococcal meningitis. Other vaccines that have recently been licensed have also
been suggested, such as rotavirus, hepatitis A, Haemophius influenzae type b and
chickenpox. Below is a summary of the vaccines in question:
Cholera vaccine: The traditional vaccine
against cholera (killed whole-cell) presents low efficacy and high reactogenicity, and as
a result, is not recommended for epidemic control. New vaccines that may be considered for
use include a killed whole-cell vaccine supplemented with recombinant subunit B of the
cholera toxin and an attenuated oral vaccine. Existing information for the first vaccine
indicates that two doses administered with a two-week interval to the population over 1
year of age will reduce the number of cases during a cholera epidemic, but it will not
eliminate the probability of an epidemic occurring in the two years following vaccination.
This is due to the rapid decrease of protection over time. In children under 5, protection
disappears after 6 months. For the live, attenuated vaccine, there is no information
available at this time to support its use.
Typhoid fever vaccine: The traditional
vaccine against typhoid fever (killed whole-cell) presents low efficacy and high
reactogenicity, and as a result is not recommended for epidemic control. The live,
attenuated, oral vaccine requires of four doses, administered in a strict regimen, which
requires special infrastructure (the vaccine is very heat labile and requires
refrigeration). The polysaccharide vaccine is effective only in populations over two years
of age.
Rotavirus vaccine: This is a recently
licensed vaccine in the United States. Field studies have demonstrated its effectiveness
in preventing severe cases of the disease (diarrheal diseases with dehydration), thus
reducing the need for hospitalization. Three doses of vaccine are required with at least
one-month intervals. The effectiveness of this vaccine has not been verified in
emergencies, it is expensive, and there is limited availability.
Haemophilus influenzae type b vaccine:
This vaccine has had a significant impact on meningitis, pneumonia and other invasive
forms of the disease, once introduced into routine immunization programs. The disease is
not epidemic and as a result is not considered a problem in disaster situations. The
disease occurs in children under 2 years of age, and to induce protection at least 2 doses
are required with a minimum interval of 1 month. PAHO promotes the introduction of this
vaccine into routine immunization programs, but the sustainability of the vaccine supply
should be assured.
Meningococcal vaccines: These vaccines have
been used to control meningococcal meningitis due to Groups A and C in epidemic
emergencies. Once epidemiological surveillance determines an increase in incidence and
identifies the responsible serogroup (A and/or C), age group, and affected area or region,
then vaccination can be considered. A stock of meningococcal vaccine should be established
in order to ensure immediate availability for outbreak control if needed. Vaccination
during non-epidemic periods is not considered to be an effective measure because of the
short duration of immunity in the infant population.
Hepatitis A vaccine: In Central America,
infection with the hepatitis A virus occurs at an early age. Recent data show that in
Nicaragua, children from 2 to 4 years of age present a seroprevalence of 73%.
Pathogenicity varies with age and is more serious in adults. In children under 6 years,
infection is asymptomatic (greater than 70%). The vaccine is expensive and two doses are
applied in children over 2 years of age, which means that its use is not justified in
emergencies.
Chickenpox vaccine: There is no
recommendation for the use of chickenpox vaccine in disaster situations.
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