Product Features of Lankeqing

Feature 1
The vaccine strain (R98) developed by Lan Keqing was naturally attenuated and not artificially weakened by Professor Cai Baoxiang from Nanjing Agricultural University in 1998, when it was isolated from healthy pigs at a farm in Gaochun, Jiangsu Province. The development of Lan Keqing required a decade of dedicated research efforts by a two-generation team of scientists and company researchers.

Feature 2

The R98 strain is a classic American-type strain, exhibiting 99.5% homology in its full gene sequence with the international reference strain VR2332.
Comparative analysis of full-genome sequence homology between Lanke Qing strain and vaccine strains as well as wild virus isolates

Feature 3
The R98 strain exhibits stable virulence without reversion to higher virulence. Research conducted by Professor Jiang Ping's team at Nanjing Agricultural University over the past decade on the stability and safety of the R98 strain demonstrated its excellent genetic stability: repeated transmission in pigs did not enhance virulence, nor did it undergo gene deletion or recombination. After 80 passages in cells, its immunogenicity remained consistent, with all generations of the virus producing robust neutralizing antibodies; post-immunization antibody titers ranged from 1.1 to 1.8.

Comparison of Immunogenicity Between Different Generation Viruses Vaccinated in Swine

Feature 4
1. The R98 strain exhibits low virulence and excellent safety profile. Immunization of lactating piglets with a 10-fold vaccine dose or pregnant sows at 85-90 days of gestation did not induce any adverse reactions.
Safety and Stability Evaluation Studies for the R98 Strain 

2. The R98 strain exhibits significantly shorter viral shedding duration compared to highly pathogenic vaccine strains and demonstrates lower residual virulence.

 Comparison of viral shedding duration in blood after immunization with various commercialized vaccine strains

Feature Five

Lankeqing not only provides excellent immune protection against classic wild virus strains, but also exhibits cross-protection against highly pathogenic wild strains and NADC30-like wild strains. When infected with different circulating strains, it significantly shortens viremia duration, alleviates clinical symptoms, reduces disease progression, and lowers mortality rates, thereby substantially minimizing losses. Following disease outbreak in pig farms, maternal immunity markedly decreases the incidence of reproductive disorders in sows and improves neonatal pig survival rates.

1. After immunization with Blancaqing, piglets can effectively resist infection by the FJ1402 strain (a highly virulent strain similar to NADC30).

2. After immunization with Blancaq, piglets exhibit strong resistance against attacks by various wild virus strains.

3. Comparison of clearance times for wild-type virus in blood under different immunization doses administered to Lan Keqing

4. Comparison of Farrowing Rates Between Lankeqing and Imported Vaccines After Immunization of Sows in a Pig Farm With Clinical Cases

 
Usage Guide

1. By leveraging the site-specific effect of attenuated vaccine strains, long-term and stable herd immunity can be established in pig farms, thereby reducing the risk of infection by wild strains. The recommended usage method for Lankeqing is as follows:
A. Stable Pig Farm
Breeding sow herd: Administer the vaccine free of charge 3-4 times per year, with 2 doses administered each time.
Piglet herd: 14-21 days of age, with one dose of immunization administered.
B.Unstable Pig Farm
Breeding sow herd: For seven days prior to and after vaccination, add broad-spectrum antibiotics (e.g., tilmicosin, tylosin, amoxicillin) and antipyretic analgesics (e.g., aspirin, nitrophenoxylamine, carbapirine calcium) to the feed for pharmacological management. Conduct pilot trials on pregnant sows; if no abnormalities are observed, administer universal vaccination to two sows first, followed by a booster dose to two sows after four weeks, then administer universal vaccination once every 3-4 months to two sows each time. Piglet herd: Administer one dose of vaccine at 7-10 days of age and another at 28-35 days of age; alternatively, determine the vaccination age based on the onset of disease in the current batch of nursery pigs (preferably administered at least four weeks before disease onset). Nasal administration may also be performed for piglets aged 7-10 days, with one dose administered.
The live vaccine against blue ear disease is not recommended for boars; however, monthly monitoring of semen for blue ear disease virus carriage is required. If positive results are detected, the use of semen from this boar should be suspended.

Immunization Precautions:
·Prior to use, the system should be employed to assess the infection status of porcine blue ear disease virus in the farm, as well as detect infections by pathogens such as pseudorabies virus, swine fever virus, and circovirus, to determine whether an immunization control program should be implemented.
·When implementing herd immunity, small-scale trials should first be conducted to confirm the absence of any adverse reactions before proceeding.
·Swine with weakconstitutions or those that have developed disease should be culled or isolated for treatment; vaccination is generally not recommended.
·During use, all types of stress should be avoided as much as possible, as animals in a state of high stress or disease can impair immune efficacy.

II. Disease prevention and control in pig farms constitutes a comprehensive systematic project that relies not only on vaccine-based immunization interventions but also requires other preventive measures, which is particularly evident in the management of blue ear disease. Alternative measures available include:
·Group-wide pharmaceutical intervention: Add broad-spectrum antibiotics (timicoxing, tylosin, florfenicol, etc.) to the feed for 7 days before and after vaccination immunization.
·Virus elimination:The afected nursery pig herd shall first undergo virus elimination, followed by cleaning, disinfection, and emptying the pens for at least 15 days before introducing new pigs.
·The 200-Day Group Sealing Program: Introduce all replacement sows required for the next 200 days in a single batch; during this period,no new animals shall be introduced,and semen from other pig farms shall not be used.
·Change the production mode:Where feasible,sitch from continuous production to two-point or three-point production modes.
·The 10 Golden Rules of Biosafety: These guidelines can serve as a reference for qualified pig farms to implement and effectively interrupt the circulatory transmission of porcine reproductive and respiratory syndrome virus (PRRSV) within pig farms.

Appendix: The 10 Golden Rules of Biosafety (Rathkjen and Dall, Acta Vet Scand (2017) 59:4)