Trends in Vaccination Practices for Respiratory Diseases on U.S. Swine
By USDA NAHMS - Vaccinating swine to prevent disease is a common management practice among U.S. swine producers. The choice of vaccines administered depends on the risk of disease, stage of production, and age of the animal. Vaccination effectiveness often depends on vaccine quality and the timing of administration.Survey Details
The USDA’s National Animal Health Monitoring
System (NAHMS) collected data on swine health
and management practices from a stratified random
sample of swine production sites in 17 States¹ as
part of the Swine 2000 study.
These sites represented 94 percent of the U.S. pig inventory
and 92 percent of U.S. pork producers with 100 or
more pigs. Overall, 2,499 swine production sites
participated in the first interview from June 1, 2000,
through July 14, 2000. A second interview was
completed by 895 of these sites between August
21, 2000, and November 3, 2000.
For estimates in
this report, small, medium, and large sites refer to
sites with less than 2,000, 2,000 to 9,999, and
10,000 or more pigs in total inventory, respectively.
For estimates involving breeding females, small,
medium, and large sites refer to sites with less than
250, 250 to 499, and 500 or more breeding
females, respectively.
Vaccination Against PRRS
In 2000, the percentage of total sites
vaccinating pigs against Porcine Reproductive and
Respiratory Syndrome (PRRS) remained similar to
that of 5 years previously (28.3 percent and 27.7
percent, respectively).
The PRRS vaccine was
used more frequently on sites with breeding
females (37.1 percent of sites) than on sites with
weaned market pigs (5.2 percent of sites). This
accounted for 53.5 percent of all breeding
females and 6.4 percent of all weaned market pigs.
Based on the number of breeding females, many
more large and medium sites (69.4 percent and
60.8 percent, respectively) vaccinated against
PRRS than small sites (30.6 percent) (Table 1).
Table 1. Percent of Sites that Vaccinated Breeding Females for PRRS, Mycoplasma, or Influenza in the Previous 6 Months, by Site Size. |
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Site Size (June 1, 2000, Sow and Gilt Inventory) |
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Vaccination Type | Small (< 250) |
Medium (250-499) |
Large (500 or More) |
All sites |
PRRS | 30.6 | 60.8 | 69.4 | 37.1 |
Mycoplasma | 15.3 | 43.6 | 46.2 | 20.9 |
SIV (H1N1) | 4.4 | 39.4 | 42.4 | 11.2 |
SIV (H3N2) | 5.0 | 29.4 | 41.5 | 10.6 |
For sites with breeding females, modified live PRRS
vaccine was the predominant type of vaccine used
(29.9 percent of sites) while only 7.1 percent of
these sites used killed PRRS vaccine, and 1.0
percent used autogenous vaccine. However,
autogenous vaccine was used on 7.4 percent of
large sites. The majority (80.6 percent) of sites that
vaccinated breeding females against PRRS
vaccinated at the time of entry into the breeding
herd.
For sites with weaned market pigs, none of the
large sites vaccinated these pigs against PRRS,
compared to 8.2 percent and 4.6 percent of
medium and small sites, respectively (Table 2).
Table 2. Percent of Sites that Vaccinated Weaned Market Pigs for PRRS, Mycoplasma, or Influenza in the Previous 6 Months, by Site Size. |
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Site Size (June 1, 2000, Total Inventory) |
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Vaccination Type | Small (< 2,000) |
Medium (2,000-9,999) |
Large (10,000 or More) |
All sites |
PRRS | 4.6 | 8.2 | 0.0 | 5.2 |
Mycoplasma | 33.9 | 65.5 | 55.2 | 40.0 |
SIV (H1N1) | 2.7 | 12.8 | 22.5 | 4.8 |
SIV (H3N2) | 3.1 | 12.7 | 17.1 | 5.0 |
Vaccination Against Mycoplasma Pneumonia
While only 20.9 percent of sites with breeding
females vaccinated these pigs against Mycoplasma
pneumonia in the previous 6 months, 40.0 percent
of sites with weaned market pigs vaccinated
against Mycoplasma pneumonia. This accounted
for 39.7 percent of all breeding females and 62.8
percent of all weaned market pigs. As was the case
with PRRS vaccine, more large and medium sites
with breeding animals vaccinated against
Mycoplasma than small sites.
The majority (74.6
percent) of sites that vaccinated breeding females
against Mycoplasma vaccinated them as young
gilts prior to entering the breeding herd. For sites
with weaned market pigs, fewer small sites
vaccinated against Mycoplasma than medium or
large sites.
Vaccination Against Swine Influenza Virus (SIV)
For the Swine 2000 study, the H1N1 influenza
virus was referred to as Traditional swine flu and
the H3N2 influenza virus was referred to as New
swine flu. Overall, 11.2 percent of sites with
breeding females administered the H1N1 vaccine
to these pigs during the previous 6 months, while
10.6 percent administered the H3N2 vaccine.
Among all sites with breeding females, 7.6 percent
used both vaccines. Thirty-eight percent of all
breeding females were on sites that administered
the H1N1 vaccine, while 37.2 percent were on sites
that administered the H3N2 vaccine. Among all
breeding females, 31.0 percent were on sites that
administered both vaccines. As with PRRS and
Mycoplasma vaccines, more large and medium
sites with breeding animals vaccinated against
H1N1 or H3N2 than small sites.
Almost 10 percent
of large sites vaccinated breeding females with
autogenous H3N2 vaccine. Of those sites with
breeding herds that used SIV vaccine, the majority
vaccinated breeding females against H1N1 (71.4
percent) or against H3N2 (75.5 percent) at the time
of entry into the breeding herd.
Only 4.8 percent of sites with weaned market
pigs vaccinated against H1N1, and 5.0 percent
vaccinated against H3N2. Among all sites with
weaned market pigs, 3.7 percent used both
vaccines. This accounted for 12.5 percent of all
weaned market pigs being on sites that
administered H1N1 vaccine and 13.3 percent being
on sites that administered H3N2 vaccine.
Among all
weaned market pigs, 10.5 percent were on sites
that administered both vaccines. For sites with
weaned market pigs, fewer small sites vaccinated
against H1N1 or H3N2 than medium or large sites.
The average age weaned market pigs were
vaccinated against H1N1 was 8.6 weeks, and
against H3N2 the average age was 9.0 weeks.
1. Arkansas, Colorado, Illinois, Indiana, Iowa, Kansas, Michigan,
Minnesota, Missouri, Nebraska, North Carolina, Ohio, Oklahoma,
Pennsylvania, South Dakota, Texas, Wisconsin.
For more information, contact:
USDA:APHIS:VS, CEAH, NRRC, Building B., M.S. 2E7
2150 Centre Ave., Bldg. B.,
Fort Collins, CO 80526
(970) 494-7000
[email protected]
www.aphis.usda.gov/vs/ceah/cahm
Source: USDA National Animal Health Monitoring Service - March 2003